Answer:
Step-by-step explanation:
We know the bottom of the triangle is 5 cm and the top of the rectangle is 5 cm, but we need to find the sides.
The height of the triangle is 8 cm, we know this as we do 18 - 10 = 8 because we subtract the rectangle from the whole figure which leaves us the triangle.
We split the triangle into 2 parts. The bottom part is now each 2.5 cm.
Then we use the Pythagorean theorem.
Check my work on the picture for how I do it for which it leads to the sided of the triangle.
Now adding the sides of the whole perimeter we just focus on the outer regions.
Two parts from the triangle which both add up to 15.20 cm and the rectangle is 25 cm, you ignore the segment inside the figure.
25 + 15.20 = 37.20 cm.
