In this page semicircle we are going to see how to find area and perimeter (circumference) of a semi-circle. To understand this topic much better we have given different kinds of example problems.

Semicircle is exactly half the entire circle.

**Area of Semi-circle = (1/2)** **Π r²**

Here r represents the radius of the circle. Now let us see example problems based on the above formula.

**Example 1:**

Find the area of the semi-circle whose radius is 7 cm.

Solution:

**Area of Semi-circle = (1/2)** **Π r²**

Here r= 7 cm and Π = 22/7

= (1/2) x (22/7) x 7²

= (1/2) x (22/7) x 7 x 7

= 1 x 11 x 7

= 77 cm²

**Example 2:**

Find the area of the semi-circle whose radius is 3.5 cm.

Solution:

**Area of Semi-circle = (1/2)** **Π r²**

Here r = 3.5 cm and Π = 22/7

= (1/2) x (22/7) x (3.5)²

= (1/2) x (22/7) x 3.5 x 3.5

= 1 x 11 x 0.5 x 3.5

= 19.25 cm²

Now let us see formula to find the perimeter (circumference) of a semi-circle.

**Perimeter of semi circle = (Π+2)r**

__Example 1 :__

Find the circumference of the semi-circle whose diameter is 7 cm.

r = diameter/2

r = 7/2

r = 3.5

Now we can apply the formula

**Circumference of semi-circle = (Π + 2)r**

here r = 3.5 and Π = 22/7

= [(22/7) + 2]x 3.5

= (22+14) x 0.5

= 36 x 0.5

= 18 cm

**Example 2 :**

Find the circumference of the semi-circle whose diameter is 42 cm.

r = diameter/2

r = 42/2

r = 21

Now we can apply the formula

**Circumference of semi-circle = Πr**

here r = 21 and Π = 22/7

= (22/7) x 21

= 22 x 3

= 66 cm

**Example 3 :**

Find the circumference of the semi-circle whose diameter is 56 cm.

r = diameter/2

r = 56/2

r = 28

Now we can apply the formula

**Circumference of semi-circle = Πr**

here r = 28 and Π = 22/7

= (22/7) x 28

= 22 x 4

= 88 cm

**Related Topics**

**Perimeter of sector****practice questions with solution****Length of arc****Practice questions on length of arc****Perimeter of square****Perimeter of parallelogram****Perimeter of rectangle****Perimeter of triangle****Area of a circle****Area of Quadrant****Area of sector****Area of triangle****Area of equilateral triangle****Area of scalene triangle****Area of square****Area of rectangle****Area of parallelogram****Area of rhombus****Area of trapezium****Area of quadrilateral****Area around circle****Area of pathways****Area of combined shapes**