Question

Santiago wants the lateral surfaces of the ramp to be painted red. how many squares feet of the ramp will be painted red?​

Answer 1

the answer is 602.4 feet square

Explanation:

(20+8.5+21.7)= 50.2

then 50.2x12=602.4 feet square

Answer 2

262 square feet

Explanation:

The lateral surface is the side surfaces, except top and bottom.

There are 3 lateral surfaces.

The 2 sides are triangles with length 20 and height 8.5

And

The back is a rectangle with length 12 and height 8.5

We sum up all the 3 surface areas, that will give us the answer.

Area of triangle is (0.5) * length * height

So,

Area of 1 triangle = 0.5 * 20 * 8.5 = 80

Area of 2 triangles = 80 * 2 = 160

Area of rectangle = length * height

so,

Area of back rectangle = 12 * 8.5 = 102

Total Lateral Surface Area = 160 + 102 = 262 square feet