Question

What is the area of a semi circle of radius 5 cm

Answer 1

If we equally divide a circle into two parts,the divided parts will be known as the semicircle.

So according to the definition,the area of semicircle = Half of the area of circle= πr²/2

By applying the data mentioned in the question;

= πr²/2

= π×5²/2

= π×12.5

= 22×12.5 / 7

= 39.28

So,the area of that semicircle is approximately 39.28cm²

Answer 2

$\bold{39.286 \mathrm{cm}^{2}}$ is the area of a semi-circle.

Given:

Radius of the circle = 5cm  

To find:

Area of the semi-circle =?

Solution:

To find the area of the semi-circle first step is to substitute the radius in the formula and then simplifying the area of the semi - circle can be obtained.

Area of the semi-circle $=\frac{\pi r^{2}}{2}$

Substituting the value of the radius in the above formula

$=\frac{\pi \times 5 \times 5}{2}$

Substituting the value of $\pi=\frac{22}{7}$

$=\frac{22 \times 5 \times 5}{7}$

Simplifying we get the area of the semicircle

$=\frac{22 \times 25}{7 \times 2}=\frac{275}{7}=39.286 \mathrm{cm}^{2}$

Therefore, the area of the semi-circle is $\bold{39.286\mathrm{cm}^{2}.}$