If the side of a square is doubled and then increased by 7, the new perimeter is 8 more then 3 times the old perimeter. what is the side of the original square?

Let the side of the original square be x. The perimeter is 4x.
The new side of the square is 2x+7 and the new perimeter is 4(2x+7)=8x+28.
So 8x+28=12x+8. 4x=20, so x=5, the side of the original square.

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct

Multiplication property of zero