Question

100 POINTS

The base of a prism is an equilateral triangle with an area of 73.2 square centimeters. The area of each lateral face is 104 square centimeters. Riley incorrectly claims that the surface area is 250.4 square centimeters.
1. What is the correct surface area?
2. What could have been Riley's error?

Answer 1

Prism means two bases of equatorial triangle

So

Total area of bases

• 2(73.2)=146.4

Total Lateral surface area

• 3(104)
• 312

So

TSA:-

• 312+146.4
• 458.4cm²

Relly made error in LSA

Answer 2

Given:

• Area of base of prism = 73.2 cm²
• Area of each lateral face = 104 cm²

Question 1

Total surface area = 2 x base area + 3 x lateral face area

= 2 x 73.2 + (3 x 104)

= 146.4 + 312

= 458.4 cm²

Question 2

Riley calculated the area by adding 2 base areas and only one lateral face.