Question

HELP!!!!!!!!!!!!

A rectangle is 5 feet wide and 3x – 5 feet long. It has the same area as a triangle with a height of 10 feet and a base of x + 3 feet. What is the area of the triangle? Area of rectangle: A=lw Area of triangle: A=12bh x =

Answer 1

Area of triangle= 35

x = 4

Explanation:

The formula for area of rectangle = length x width.

Area of triangle = (1/2)bh

It's stated these two areas are equal:

(5)(3x - 5) = (1/2)(x + 3)(10)

Distribute on both the left side and the right side.

15x - 25 = (5)(x + 3)

15x - 25 = 5x + 15

Subtract 5x from both sides and add 25 to both sides.

10x = 40

Divide:

x = 4

Plug this back into the area of triangle:

= (1/2)(x + 3)(10)

= (1/2)(4 + 3)(10)

= (1/2)(7)(10)

= (1/2)(70)

= 35