Idon't understand, can someone me ?

When you find the perimeter of the shape you add all the sides. That what you'll be doing to each shape except you don't know X. But you can combine like terms.

in  the rectangle in order to find the perimeter it will be set up like this...

x + 5 + x + 5 + x + x = P

P= perimeter of rectangle

if you're wondering why I am adding 2 same numbers well because the opposite side of a rectangle is the same. so the side of x + 5 the other side should be x + 5 as well

combine like terms

x + 5 + x + 5 + x + x = P

x + 5 + x + 5 + x + x = P

x + x + x + x = 4x

5 + 5 = 10

4x + 10

one the triangle you do the same except the part you have the same numbers twice. All the numbers are given to you just add the like terms together.

for problem a, it siad both of these shapes have the same perimeter therefore you set your two equation equal to each other

4x + 10 = the other equation for the triangle

find X. I hope you know how to do that

after finding X plug in to you x and find the perimeter for each shape. They should have the same number.

it should be a and d. lmk if i'm wrong xd