16Hit1600
Geometry and TrigonometryMediumSurface area of a rectangular box

Geometry and Trigonometry practice question

A closed rectangular box has dimensions 4 by 5 by 6. What is its total surface area?

  1. A. 148Correct
  2. B. 120
  3. C. 74
  4. D. 296

Answer: A. 148

A box has three pairs of identical faces: 4 × 5, 4 × 6 and 5 × 6. Surface area is 2(20 + 24 + 30) = 2(74) = 148.

Why the other answers are wrong

B. 120
120 is the VOLUME, 4 × 5 × 6. Surface area adds the areas of the faces.
C. 74
74 is the area of one face of each pair. The box has two of each, so double it.
D. 296
296 doubles the total twice. Each of the three face areas is counted exactly twice: 2 × 74.

More Geometry and Trigonometry questions

Not affiliated with the College Board. SAT is a trademark of the College Board.