Question

The base of a prism is a right-angled triangle having base and altitude 3 and 4 cm respectively. The lateral surface area of the prism if the height of prism is 10 cm will be equal to_____

• A. $140c{m}^2$
  
• B. $120c{m}^2$
  
• C. $80c{m}^2$
  
• D. $100c{m}^2$

Answer 1

The correct option is B

$120c{m}^2$

Base of the prism is a right-angled triangle having base and altitude 3 and 4 cm respectively.

Third side of the triangle = $\sqrt{3^2+4^2}=5cm$

Lateral Surface Area = $BasePerimeter\times height$

$=(5+3+4)10$

$=120c{m}^2$