The area the a one is the space occupied by the one in a two-dimensional plane. Alternatively, the space occupied in ~ the boundary/circumference the a one is dubbed the area the the circle. The formula because that the area of a circle is A = πr2, wherein r is the radius that the circle. The unit of area is the square unit, because that example, m2, cm2, in2, etc. Area of one = πr2 or πd2/4 in square units, where (Pi) π = 22/7 or 3.14. Pi (π) is the ratio of circumference to diameter of any type of circle. The is a special mathematical constant.

You are watching: Find the area of a circle with a diameter of 12 inches. use 3.14 for pi.

The area of a one formula is useful for measuring the region occupied through a circular field or a plot. Suppose, if you have a circular table, climate the area formula will help us to know how much towel is necessary to cover it completely. The area formula will certainly also help us to recognize the boundary length i.e., the one of the circle. Does a circle have actually volume? No, a circle doesn't have a volume. A circle is a two-dimensional shape, the does not have volume. A one only has an area and perimeter/circumference. Permit us learn in detail around the area that a circle, surface area, and also its circumference v examples.

 1 Circle and Parts that a Circle 2 What Is the Area that Circle? 3 Area of one Formulas 4 Derivation that Area of a one Formula 5 Surface Area of one Formula 6 Real-World example on Area of Circle 7 FAQs top top Area that Circle

## Circle and Parts the a Circle

A circle is a collection of points that space at a solved distance from the center of the circle. A one is a closeup of the door geometric shape. We see circles in day-to-day life such as a wheel, pizzas, a circular ground, etc. The measure up of the room or region enclosed inside the one is well-known as the area the the circle.

Radius: The street from the center to a point on the boundary is dubbed the radius of a circle. The is stood for by the letter 'r' or 'R'. Radius plays critical role in the formula for the area and circumference that a circle, which we will learn later.

Diameter: A line that passes with the center and its endpoints lied on the one is referred to as the diameter of a circle. It is represented by the letter 'd' or 'D'.

Diameter formula: The diameter formula that a circle is double its radius. Diameter = 2 × Radius

d = 2r or D = 2R

If the diameter that a circle is known, that is radius deserve to be calculated as:

r = d/2 or R = D/2

Circumference: The circumference of the circle is same to the size of the boundary. This means that the perimeter of a circle is equal to its circumference. The length of the rope the wraps approximately the circle's border perfectly will certainly be equal to its circumference. The below-given number helps girlfriend visualize the same. The circumference can be measured by using the provided formula:

where 'r' is the radius of the circle and also π is the mathematical continuous whose value is approximated come 3.14 or 22/7. The circumference of a circle have the right to be supplied to discover the area of the circle.

For a circle with radius ‘r’ and circumference ‘C’:

π = Circumference/Diameterπ = C/2r = C/dC = 2πr

Let us understand the different parts the a circle using the following real-life example.

Consider a circular-shaped park as displayed in the figure below. We have the right to identify the assorted parts of a circle v the help of the figure and table given below.

In a CircleIn ours parkNamed by the letter
CentreFountainF
CircumferenceBoundary
ChordPlay area entrancePQ
RadiusDistance from the fountain to the enntrance gate gateFA
DiameterStraight heat Distance between Entrance Gate and Exit Gate with the fountainAFB
Minor segmentThe smaller area that the park, i beg your pardon is presented as the pat area
Major segmentThe enlarge area the the park, other than the beat area
Interior component of the circleThe green area of the whole park
Exterior part of the circleThe area outside the border of the park
ArcAny curved component on the circumference.

The area the a one is the quantity of space enclosed within the border of a circle. The region within the border of the circle is the area inhabited by the circle. It may also be described as the total variety of square systems inside that circle.

The area of a circle have the right to be calculation in intermediate actions from the diameter, and also the one of a circle. Indigenous the diameter and also the circumference, us can discover the radius and then discover the area the a circle. Yet these formulae administer the shortest method to uncover the area the a circle. Suppose a circle has actually a radius 'r' climate the area of circle = πr2 or πd2/4 in square units, where π = 22/7 or 3.14, and also d is the diameter.

Area of a circle, A = πr2 square units

Circumference / Perimeter = 2πr units

Area the a circle have the right to be calculate by using the formulas:

Area = π × r2, whereby 'r' is the radius.Area = (π/4) × d2, where 'd' is the diameter.Area = C2/4π, whereby 'C' is the circumference.

### Examples making use of Area of one Formula

Let us think about the following illustrations based upon the area of circle formula.

Example1: If the length of the radius the a circle is 4 units. Calculate its area.

Solution:Radius(r) = 4 units(given)Using the formula because that the circle's area,Area that a one = πr2Put the values,A = π42A =π × 16A = 16π ≈ 50.27

Answer: The area the the circle is 50.27 squared units.

Example 2: The length of the biggest chord the a circle is 12 units. Discover the area that the circle.

Solution:Diameter(d) = 12 units(given)Using the formula for the circle's area,Area the a circle = (π/4)×d2Put the values,A = (π/4) × 122A = (π/4) × 144A = 36π ≈ 113.1

Answer: The area of the one is 113.1 square units.

## Area that a Circle using Diameter

The area the the one formula in regards to the diameter is: Area of a one = πd2/4. Below 'd' is the diameter the the circle. The diameter that the one is twice the radius that the circle. D = 2r. Generally from the diameter, we require to first find the radius the the circle and then find the area that the circle. V this formula, we can straight find the area of the circle, from the measure up of the diameter that the circle.

## Area of a Circle making use of Circumference

The area of a circle formula in regards to the one is provided by the formula (dfrac(Circumference)^24pi). There room two an easy steps to find the area that a circle from the provided circumference the a circle. The one of a circle is very first used to find the radius the the circle. This radius is further useful to uncover the area that a circle. However in this formulae, we will be able to directly discover the area of a circle from the one of the circle.

## Area of a Circle-Calculation

The area of the circle have the right to be conveniently calculated one of two people from the radius, diameter, or circumference of the circle. The consistent used in the calculate of the area that a one is pi, and also it has a fractional numeric value of 22/7 or a decimal value of 3.14. Any of the worths of pi deserve to be used based upon the requirement and also the need of the equations. The listed below table mirrors the list of formulae if we know the radius, the diameter, or the circumference of a circle.

 Area of a circle as soon as the radius is known. πr2 Area of a circle when the diameter is known. πd2/4 Area the a circle as soon as the circumference is known. C2/4π

Why is the area of the circle is πr2? To recognize this, let's very first understand how the formula because that the area of a one is derived.

Observe the over figure carefully, if we split up the circle into smaller sections and also arrange castle systematically it develops a form of a parallelogram. When the circle is divided into even smaller sectors, it progressively becomes the form of a rectangle. The more the number of sections that has more it tends to have actually a form of a rectangle as presented above.

The area that a rectangle is = length × breadth

When us compare the length of a rectangle and the circumference of a circle we have the right to see that the size is = ½ the one of a circle

Area of one = Area the rectangle formed = ½ (2πr) × r

Therefore, the area that the one is πr2, where r, is the radius that the circle and also the value of π is 22/7 or 3.14.

The surface ar area that a one is the same as the area of a circle. In fact, when we to speak the area the a circle, we mean nothing however its full surface area. Surface area is the area inhabited by the surface of a 3-D shape. The surface of a round will be spherical in shape yet a circle is a simple plane 2-dimensional shape.

If the length of the radius or diameter or even the one of the one is given, then we can find out the surface ar area. The is represented in square units. The surface area of circle formula = πr2 where 'r' is the radius of the circle and also the value of π is roughly 3.14 or 22/7.

Ron and his girlfriend ordered a pizza on Friday night. Each slice was 15 cm in length.

Calculate the area of the pizza the was bespeak by Ron. You deserve to assume that the length of the pizza slice is equal to the pizza’s radius.

Solution:

A pizza is circular in shape. So we can use the area that a circle formula to calculate the area that the pizza.

Area of one formula = πr2 = 3.14 × 15 × 15 = 706.5

Area that the Pizza = 706.5 sq. Cm.

Example 4: A wire is in the form of an equilateral triangle. Each side of the triangle steps 7 in. The wire is bent into the form of a circle. Find the area of the circle the is formed.

Solution:

Perimeter that the it is provided Triangle: Perimeter the the triangle = 3 × side = 3 × 7 = 21 inches.

Since the perimeter the the it is intended triangle = one of the circle formed.

Thus, the perimeter of the triangle is 21 inches.

Circumference of a circle = 2πr = 2 × 22/7 × r = 21. R = (21 × 7)/(44) = 3.34.

Therefore, the Radius of the one is 3.34 cm. Area that a circle = πr2 = 22/7 ×(3.34)2 = 35.042 square inches.

Therefore, the area the a one is 35.042 square inches.

Example 5: The time displayed in a one clock is 3:00 pm. The length of the minute hand is 21 units. Find the street traveled by the tip of the minute hand once the time is 3:30 pm.

See more: My Strange Addiction Justin Bieber Look-A-Like; Makeup Eater

Solution:

When the minute hand is in ~ 3:30 pm, it covers fifty percent of the circle. So, the street traveled through the minute hand is actually fifty percent of the circumference. Distance (= pi) (where r is the size of the minute hand). Thus the distance extended = 22/7 × 21 = 22 × 3 = 66 units. Therefore, the street traveled is 66 units.