Answer:
A) 30 cm
B) 20 cm
Explanation:
For the perimeter of rectangle B, I just imagined there was a cut horizontally through the middle. The length would be 5, since its half, and the width would be the same (10) because folding it into a rectangle only changes its length.
I added it up : 5+5+10+10= 30 cm
Rectangle B is 30 cm
For the perimeter of square C, you folded it again to make the width decrease by 5cm , so all the sides were 5cm.
5+5+5+5=20 cm
Square C is 20 cm
