Question

What is the best approximation for the perimeter of a semicircle with a diameter of 35 inches?

Use 3.14 to approximate pi.

Answer 1

Circumference shares the same concept with perimeter.

First, let's use the formula for the circumference of a full circle.

C = 2πr

Where 'π' stands for pi(22/7 or 3.14) and 'r' stands for the radius.

or

C = πd

Where 'π' represents pi(22/7 or 3.14) and 'd' stands for the diameter.

But, we are trying to find a semi-circle's circumference. So, what you would do is that you would divide the whole product of the formula by 2.

For this, I'll be using this formula C = πd. Though, since we are dividing by 2 we can apply that to the diameter and make it a radius in our formula.

So the 'd' in the formula will be 'r'.

Now, let's find the radius.

D/2 = R

So,

35/2 = 17.5

Use this in our formula:-

C = πr

C = 3.14(17.5)

C = 54.95 inches.