Question

Find the perimeter for the figure.

Round you answer to the nearest tenth.
10 cm
30 cm
20 cm
10 cm

Answer 1

30cm is the diameter of the half circle, therefore the radius is d/2=30/2=15cm.

The formula for the perimeter of circle os 2pi*r, but since it is just half a circle, we divide by 2. The perimeter for the half circle is pi*r.

Then we add all of them together

P= 10+20+10+3.14*15= 87.1cm

Answer 2

Explanation:

A semicircle has 1/2 circumference of the full circle = 1/2 pi d

so the entire perimeter will be 1/2 ( pi)(30) + 10 + 10 + 20 = 87.1 cm