Question

Two students were asked to determine the total surface area of a rectangular prism.

Neither
of the students correctly completed the task.
5 cm
5 cm
11 cm
TYSON
220 cm²
Determine what mistake each student made and correct their work.
BELLA
275 cm²

Answer 1

Answer/Step-by-step explanation:

The formula for the surface area of a rectangular prism is SA = 2B + Ph

We can create a base from two of the measurements and the height for another. I will make 5 and 5 base lengths (a square base) while 11 is the height.

SA = 2(5*5) + (5+5+5+5)(11)

2(25) + (20)(11)

270 cm²

Tyson:

SA = (5+5+5+5)(11)

(20)(11)

220 cm²

This shows that Tyson did not include the bases in the surface area, which is also known as the lateral area.

Bella:

SA = 2(5*5) + (5+5+5+5)(11) + 5

2(25) + (20)(11) + 5

275 cm²

The only way I can think Bella made a mistake is because she added 5 on accident. Otherwise, how would 270 become 275 without any major changes to the equation?