Answer:
To find the perimeter, we want to find the circumference of the whole circle, divide by 2, and add the 24 inches to get the total perimeter.
A semicircle is half a circle. If the straight edge of the semi circle is 24 inches, that makes the diameter of the full circle 24 inches as well.
To find the circumference of the full circle, we need the formula:
C = 2πr
Circumference = 2 x pi x radius
Radius is half of the diameter, so 12 inches.
C = 2 x pi x 12
C = 75.36 inches
75.36 is the circumference of a circle with a diameter of 24 inches. Divide this by two to get 37.68 inches, which is the length of the round part of the mat. Adding 24 inches for the straight side gives you the final answer, 61.68 inches, or ABOUT 62 inches.