Question

plz help

Answer 1

whats the question?

Answer 2

First you need the lengths of lines AB, BC, CD

so if AD is 40 , then solving the lengths of each lines will be
the equation

x + x + 10 + 10 = 40
( AB + BC + CD = 40)

Answer 3

I believe you can go on :)
The perimeter is the total sides of the triangle