Question

What is the best approximation for the perimeter of a semicircle with a diameter of 12 cm?

Use 3.14 to approximate pi.

18.84 cm

30.84 cm

61.68 cm

75.36 cm

Answer 1

When we speak of the word "perimeter" of a circle, we mean to say the circumference. Since we are only given a semicircle, the perimeter would be,
perimeter = (pi)(radius) + diameter
Substituting the known values,
perimeter = (3.14)(6 cm) + 12 cm
The value of the perimeter is,
perimeter = 30.84 cm