Question

An eraser is in the shape of a triangular prism. Its dimensions are shown in the diagram. What is surface area of the

eraser?
50 mm
40 mm
40 mm
30 mm
3,600 square millimeters
4.800 square millimeters
5,400 square millimeters
6,000 square millimeters

Answer 1

D) 6,000 square mm

Explanation:

To find the surface area of the triangular prism, find the are of each face.

• 40 × 30 ÷ 2 = 600 × 2 sides = 1200
• 40 × 50 = 2000
• 40 × 30 = 1200
• 40 × 40 = 1600

After adding all the sides' together, you get 6,000 square mm.

Answer 2

6000 square millimeters

Explanation:

Side length of the slanting side can be calculated using the Pythagorean theorem,

L = sqrt(30^2+40^2) = 50

sufrace area of a triangular prism

= surface area of the end sections + the surface area of the three side faces

= 2*(30*40/2) + 40*(30+40+50)

= 1200 + 4800

= 6000 mm^2