Question

A half circle is joined to an equilateral triangle with side lengths of 8 units. What is an approximate perimeter of the resulting shape?

Answer 1

Answer: 28.56 units

Explanation:

If we assume that the diameter of the half-circle will be 8 units, the shape will be something like in the image below.

Where the perimeter will be equal to the sum between the two remaining sides of the triangle (8 units each) and the curve part of the half-circle.

Knowing that the perimeter of a circle of diameter d is:

P = pi*d

pi = 3.14

In the case of a half-circle, the perimeter will be half of that:

Then the total perimeter in this shape is:

P = 8 + 8 + 3.14*8/2 = 28.56 units