Question

Find the area of a semi circle with diameter d cm​

Answer 1

`(\pi d^2)/(8)`

Explanation:

Semicircle is HALF of a circle. The area of a circle is given by:

`\pi r^2`

So, area of semi circle is:

`(\pi r^2)/(2)`

Where r is the radius (half of diameter).

The diameter is given as "d", so the radius is half of that, this would be:

`(d)/(2)`

Now, substituting this into "r", we get the expression for area of the semicircle:

Area =
`(\pi r^2)/(2)=(\pi ((d)/(2))^2)/(2)=(\pi ((d^2)/(4)))/(2)=((\pi d^2)/(4))/(2)=(\pi d^2)/(8)`

This is the area.