Question

This section of a concrete skateboard ramp has the shape of a triangular prism. Find the volume of the triangular prism. Find the value of the concrete used in the ramp if the cost of concrete is $ 4.00 per cubic foot.

Answer 1

The volume of the triangular prism: 59.2
`ft^(3)`

The value of the concrete used is: 16*4 = $64

Explanation:

I think your question is missed of key information, allow me to add in and hope it will fit the original one. Please have a look at the attached photo

My answer:

As we know that, the formula to find out the volume of the triangular prism is:

V =
`(1)/(2) a*b*h` when h is the height and a&b are the length of the two square edges. So we have:

• V =
  `(1)/(2)`*4*4*7.4 = 59.2
  `ft^(3)`

To find the concrete used in the ramp if the cost of concrete is $ 4.00 per cubic foot, we need to know the area of the ramp, which is:

S = 4*4 = 16
`ft^(2)`

Hence, the value of the concrete used is: 16*4 = $64

Answer 2

Explanation:

Given:

Base dimension:

Side, b = 4 ft

Height, hb = 4 ft

Height, h = 7.4 ft

Volume of a prism, V = base area, A × height, h

Base = triangle

Area of a triangle, A = 1/2 × b × hb

= 1/2 × 4 × 4

= 8 ft^2

Volume, V = 8 × 7.4

= 59.2 ft^3

cost of concrete = $ 4.00 per cubic foot

Therefore, 59.2 ft^3 of triangular prism.

= $4/1 ft^3 × 59.2 ft^3

= $236.8

Cost of concrete used in the ramp = $236.8