Question

What is the surface area? 4 ft 5 ft 2

Answer 1

We have a rectangular prism, that has length of 5 ft, width of 4 ft and height of 2 ft.

The surface area is the sum of the area of the faces.

In this case we have 6 faces, that can be grouped in pairs, as there are 3 pairs of equal faces:

>> Two faces (A1) of dimensions 4 ft * 5 ft

>> Two faces (A2) of dimensions 5 ft * 2 ft

>> Two faces (A3) of dimensions 4 ft * 2 ft

Then, we can sum the area of the faces as:

`\begin{gathered} A=2\cdot A_1+2\cdot A_2+2\cdot A_3 \\ A=2\cdot(4\cdot5)+2\cdot(5\cdot2)+2\cdot(4\cdot2) \\ A=2\cdot20+2\cdot10+2\cdot8 \\ A=40+20+16 \\ A=76 \end{gathered}`

Answer: the surface area is 76 square feet.