Question

A Shpere and Hemisphere has radius '$r$'. (TSA - total surface area; CSA - Curved surface area)

• A. $4\pi r^2$
• B. $2\pi r^2$
• C. $3\pi r^2$

Answer 1

Sphere: Radius = r,

TSA of Sphere
$=4\pi r^2$

Hemisphere: Radius = r
CSA of Hemisphere
$=2\pi r^2$

TSA of Hemisphere

= CSA of Hemishere + Area of Circular Base
$=2\pi r^2+\pi r^2=3\pi r^2$