Ms. Wilson purchased a

welcome mat for her front

porch that is a semicircle. The

straight side of the mat is 38

inches. To the nearest inch,

what is the perimeter of the

mat?

Answer: 97.7 in

Step-by-step explanation: The perimeter is another name for circumference. Since we know that the formula for circumference is 2 (pi) r, but we only want half of that.

Note that 2r is another way of writing the diameter (d).

In this case, we can use the formula d (pi) / 2 + d (we're adding d because d (pi) / 2 will only give us the perimeter of the arch.

38 (pi) / 2 = 59.66

59.66 + 38 = 97.66

Rounded, that would be 97.7 in