Help me please I don’t understand

Explanation:

The perimeter around the circle, aka circumference, is found through this formula

C = 2*pi*r

That's for a full circle. However, we're dealing with semicircles here, so we cut that in half to get pi*r to represent the curved distance around half the circle.

For the outer larger semicircle, that curved distance is exactly 14pi

For the inner smaller semicircle, that curved distance is 7pi, since 7 is half of 14.

The total curved portions is 14pi+7pi = 21pi

Then we add on the last straight line portion that's 14 cm long to get a total perimeter of 21pi+14

This is the exact perimeter in terms of pi.

The last thing to do is replace pi with 3.14 and simplify

21pi+14 = 21*3.14+14 = 79.94

This value rounds to 80