### Circle Area Calculator - Enter radius and calculate the circle area

## Area of Circle Formula

### Formula to calculate **Area** of a **Circle** using **Radius**

#### Area = πr²

#### r is radius and Pi value is 3.14

### Find the **Radius** of a **Circle** for a given **Area**

#### Radius = square root (A / π)

#### A is area and Pi value is 3.14

### Formula to calculate **Perimeter** of a **Circle** using **Radius**

#### Perimeter = 2πr

#### r is radius and Pi value is 3.14

### Find the **Radius** of a **Circle** for a given **Perimeter**

#### Radius = square root (C / 2π)

#### C is Circumference or Perimeter and Pi value is 3.14

## Area of Sector Formula

### Formula to calculate **Area** of a **Sector**

#### Area =(θ/360°) x πr²

#### r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

### Formula to calculate **Perimeter** of a **Sector**

#### Perimeter = 2r + ((θ/360) × 2πr )

#### r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

## Area of Oval Formula

**Area of Oval Formula**

#### Area = π(A + B)/2

#### A is Major Axis, B is Minor Axis and Pi value is 3.14

### Formula for **Perimeter** of a **Oval**

#### Perimeter = 2π square root((A² + B²)/2)

#### A is Major Axis, B is Minor Axis and Pi value is 3.14

## Area of Ellipse Formula

**Area of Ellipse Formula**

#### Area = πAB

#### A is Major Axis, B is Minor Axis and Pi value is 3.14

### Formula for **Perimeter** of a **Ellipse**

#### Perimeter = π (A + B) (1 + 3h / 10 +square root( 4 - 3h))

#### A is Major Axis, B is Minor Axis , h is (A - B)² / (A + B )² and Pi value is 3.14

## Area of Rhombus Formula

### Formula to calculate **Area** of a **Rhombus**

#### Area = PQ / 2

#### P is Diagonal 1 and Q is Diagonal 2

### Find the **Perimeter** of a **Rhombus** for a given **Diagonal Value**

#### Radius = 2 * square root (P² + Q²)/2

#### P is Diagonal 1 and Q is Diagonal 2

## Area of a Parallelogram Formula

**Area** of a **Parallelogram**

#### Area = ( b*h)

#### h is height and b is base

**Perimeter** of a **Parallelogram**

#### Perimeter = 2(a + b)

#### a and b are the length of two adjacent sides of parallelogram

## Area of a Square Formula

### Formula to calculate **Area** of a **Square** using **side**

#### Area = a²

#### a is side

### Find the **side** of a **Square** for a given **area**

#### Side = Square Root (A)

#### A is area

### Formula to calculate **Perimeter** of a **Square** using **side**

#### Perimeter = 4a

#### a is side

### Find the **side** of a **Square** for a given **area**

#### Side = P / 4

#### P is Perimeter

## Area of a Rectangle Formula

### Formula to calculate **Area** of a ** Rectangle ** using Length and Width

#### Area = L * W

#### L is Length and W is Width

### Formula to calculate **Perimeter** of a ** Rectangle ** using Length and Width

#### Perimeter = 2 * (L + W)

#### L is Length and W is Width

## Triangle Area Formula

### Formula to calculate **Area** of a **Equilateral Triangle** using **Side**

#### Area = square root (3)/4 a²

#### a is side

### Formula to calculate **Area** of a **Isosceles Triangle** using **Base and Height**

#### h = square root (a² - b²/4)

#### Area = bh

#### b is base and h is Height

### Formula to calculate **Area** of a **Scalene Triangle** using **Side**

#### S = a + b + c / 2

#### Area = square root (s (s-a) (s-b) (s-c))

#### a, b and c are sides

### Formula to calculate **Perimeter** of a **Equilateral Triangle** using **Side**

#### Perimeter = 3a

#### a is side

### Formula to calculate **Perimeter** of a **Isosceles Triangle** using **base and side**

#### Perimeter = 2a + b

#### b is base and a is side

### Formula to calculate **Perimeter** of a **Scalene Triangle** using **Base and Height**

#### Perimeter = a + b + c

#### a, b and c are sides

## Trapezoid Area Formula

### Formula to calculate **Area** of a **Trapezoid** using **Axes and Height**

#### Area = 1/2 (a + b) h

#### a and b are axes and h is height

### Formula to calculate **Perimeter** of a **Trapezoid** using **Axes and Height**

#### Perimeter = (a + h + b + h)

#### a and b are axes and h is height

## Pentagon Area Formula

### Formula to calculate **Area** of a **Pentagon** using **Side**

#### Area = 1/4 square root(5 (5 + 2 square root(5)))a²

#### A is Side

### Formula to calculate **Perimeter** of a **Pentagon** using **Side**

#### Perimeter = 5a

#### a is Side

## Hexagon Area Formula

**Area** of a **Hexagon **

#### Area = 3 * square root (3) /2 a²

#### a is side

**Perimeter** of a **Hexagon **

#### Perimeter = 6a

#### a is side

## Octagon Area Formula

### Formula to calculate **Area** of a **Octagon** using **Side**

#### Area = 2(1 + square root (2))a²

#### a is Side

### Formula to calculate **Perimeter** of a **Octagon** using **Side**

#### Perimeter = 8a

#### a is Side

## Kite Area Formula

### Formula to calculate **Area** of a **Kite** using **Diagonals**

#### Area = ab/2

#### a is diagonal 1 and b is diagonal 2

### Formula to calculate **Perimeter** of a **Kite** using **Diagonals**

#### Perimeter = 2(a + b)

#### a is diagonal 1 and b is diagonal 2

## Frequently Asked Questions on Area Calculator and Area Formula

Area of a circle is πr² where r is radius and Pi value is 3.14

Area of a circle is πr² where r is radius and Pi value is 3.14

Area of triangle is square root (3)/4 a² where a is side.

Area of triangle is square root (3)/4 a² where a is side.

Area of rectangle is L * W where L is Length and W is Width

Area of rectangle is L * W where L is Length and W is Width

Area of a trapezoid is 1/2 (a + b) h where a and b are axes and h is height

Area of a trapezoid is 1/2 (a + b) h where a and b are axes and h is height

Area of scalene triangle is bh where b is base and h is Height

Area of scalene triangle is bh where b is base and h is Height

Area of square is a² where a is side

Area of square is a² where a is side

Area of parallelogram is b*h where h is height and b is base

Area of parallelogram is b*h where h is height and b is base

Diameter = 2 × r where r is radius

Diameter = 2 × r where r is radius

Area of triangle is square root (3)/4 a² where a is side

Area of triangle is square root (3)/4 a² where a is side

Perimeter of rectangle is 2 * (L + W) where L is Length and W is Width

Perimeter of rectangle is 2 * (L + W) where L is Length and W is Width

Perimeter of circle is 2πr where r is radius and Pi value is 3.14

Perimeter of circle is 2πr where r is radius and Pi value is 3.14

Area of rectangle is L * W where L is Length and W is Width

Area of rectangle is L * W where L is Length and W is Width

Area of sphere is 4πr² where r is radius and Pi value is 3.14

Area of sphere is 4πr² where r is radius and Pi value is 3.14

Area of equilateral triangle is square root (3)/4 a² where a is side

Area of equilateral triangle is square root (3)/4 a² where a is side

Area of rhombus is PQ / 2 where P is Diagonal 1 and Q is Diagonal 2

Area of rhombus is PQ / 2 where P is Diagonal 1 and Q is Diagonal 2

Area of a right triangle is ab/2 where a and b are sides

Area of a right triangle is ab/2 where a and b are sides

Perimeter of square is 4a where a is side

Perimeter of square is 4a where a is side

Area of sector (θ/360°) x πr² where r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

Area of sector (θ/360°) x πr² where r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

Area of hexagon is 3 * square root (3)/2 a² where a is side

Area of hexagon is 3 * square root (3)/2 a² where a is side

Area of semicircle is 1/2 πr² where r is radius and Pi value is 3.14

Area of semicircle is 1/2 πr² where r is radius and Pi value is 3.14

Area of parallelogram is b * h where h is height and b is base

Area of parallelogram is b * h where h is height and b is base

Area of sector is (θ/360°) x πr² where r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

Area of sector is (θ/360°) x πr² where r is radius, Pi value is 3.14 and 𝜃 is the angle of the sector.

Area of Isosceles triangle is bh where b is base and h is Height

Area of Isosceles triangle is bh where b is base and h is Height

Area of polygon is 1/2 ap where a is apothem and p is perimeter

Area of polygon is 1/2 ap where a is apothem and p is perimeter

Area of kite is ab/2 where a is diagonal 1 and b is diagonal 2

Area of kite is ab/2 where a is diagonal 1 and b is diagonal 2

Area of ellipse is πAB where A is Major Axis, B is Minor Axis and Pi value is 3.14

Area of ellipse is πAB where A is Major Axis, B is Minor Axis and Pi value is 3.14

Area of octagon is 2(1 + square root (2))a² where a is Side

Area of octagon is 2(1 + square root (2))a² where a is Side