Question

Each question has FOUR options. ONE OR MORE THAN ONE of these four options (s) is (are) correct answer(s).
The base of a solid right prism is a triangle whose sides are 25,169 , and 144 units. The height of the prism is 40 units. Find the total surface area of prism.

• A. $<15000$ sq. units
• B. $>15500sq$. units
• C. $=15320sq$. units
• D. $>15000sq$. units

Answer 1

Answer: (C), (D)

Total surface area of prism $=$ (perimeter of triangle at the base $\times$ height $)+(2\times$ area of its base)
Base of the right prism is a right triangle
So, area of base $=\frac{1}{2}\times$ base $\times$ height $=\frac{1}{2}\times 25\times 144=1800$ sq.units
Perimeter $=(25+169+144)=338$ units
So, total surface area $=(338\times 40)+1800$
$=13520+1800=15320$
sq. units. [So, (c) is correct]
And, since 15320 is $>15000$, we also conclude that (d) is also correct.