Question

A square pyramid is cut, open and laid flat as in the figure below. What is the surface area of this pyramid ?

• A. 200 square centimetres
• B. 210 square centimetres
• C. 340 square centimetres
• D. 230 square centimetres

Answer 1

Answer:

C. 340 square centimetres

Total Surface Area = (base length)² + 2 × base length × slant height

Here,

base length = 10

slant height $=\sqrt{13^2-5^2}$

$=\sqrt{169-25}$

$=\sqrt{144}$

$=12$

Total Surface Area $=10^2+2\times10\times12$

$=100+240$

$=340cm^2$