Answer:
about 24.28 cm
Explanation:
You want the perimeter of a composite figure consisting of a rectangle and a semicircle.
Perimeter
The perimeter is the sum of the side lengths. Here, that is the sum of three straight sides and the arc length of a semicircle.
The three straight sides are 7 cm, 4 cm, and 7 cm long, for a total length of ...
(7 +4 +7) cm = 18 cm
The semicircle has a diameter of 4 cm, so its arc length is ...
(1/2)πd = (π/2)(4 cm) = 2π cm ≈ 6.28 cm
The perimeter, rounded to 2 decimal places is then ...
perimeter = straight side length + curved side length
perimeter = 18 cm + 6.28 cm = 24.28 cm