i dont even know where to start..

Question

A rectangle and triangle have equal perimeters. The

rectangle has a length of 2x -5 and a width of x +4. The

triangle has side lengths: x + 4, 3x, and 8. Solve for x.

What is the perimeter of each shape?

Answer 1

The perimeter of the rectangle is 2(2x-5)+2(x+4)=4x-10+2x+8=6x-2.

The perimeter of the triangle is x+4+3x+8=4x+12.

Since they have equal perimeters we must have that 6x-2=4x+12. Therefore, 2x=14 which implies that x=7.

So the perimeter of the rectangle equals 40 and the perimeter of the triangle is also 40.