The problem asks us to find the perimeter of a figure consisting of a semicircle and three straight lines. The straight lines have lengths of 20 cm each. The semicircle has a diameter of 20 cm. We are instructed to use 3.14 as an approximation for $\pi$.

1. Problem Description

The problem asks us to find the perimeter of a figure consisting of a semicircle and three straight lines. The straight lines have lengths of 20 cm each. The semicircle has a diameter of 20 cm. We are instructed to use 3.14 as an approximation for $\pi$.

2. Solution Steps

The perimeter of the figure is the sum of the lengths of all its sides. In this case, it consists of two straight lines of length 20 cm, one straight line of length 20 cm (the diameter of the semicircle), and the arc length of the semicircle.

The circumference of a circle is given by the formula:

$C = 2 \pi r = \pi d$

where $r$ is the radius and $d$ is the diameter.

Since the figure contains a semicircle, the length of the arc is half the circumference of a full circle. Therefore, the arc length is:

$Arc\,length = \frac{1}{2} \pi d$

Given that the diameter $d = 20$ cm and we use $\pi = 3.14$, the arc length of the semicircle is:

$Arc\,length = \frac{1}{2} (3.14) (20) = (3.14)(10) = 31.4$ cm.

The perimeter is the sum of the two straight sides of length 20 cm, the straight side of length 20 cm corresponding to the diameter of the semicircle, and the arc length of 31.4 cm. Thus,

$Perimeter = 20 + 20 + 20 + 31.4 = 91.4$ cm.

3. Final Answer

The perimeter of the figure is 91.4 cm.