Question

The total surface area of a right circular cone of radius 5 cm and slant height 9 cm is . (Take $\pi =\frac{22}{7})$

• A. $220c{m}^2$
• B. $230c{m}^2$
• C. $240c{m}^2$
• D. $250c{m}^2$

Answer 1

The correct option is A $220c{m}^2$

Given, radius of the right circular cone, $r=5cm$
Slant height of right circular cone, $l=9cm$
Total surface area of a right circular cone
$=\pi r^2+\pi rl$
$=\pi r(r+l)$
$=\frac{22}{7}\times 5\times (5+9)$
$=\frac{22}{7}\times 5\times 14$
$=220c{m}^2$
$\therefore$ The total surface area of the given right circular cone is $220c{m}^2.$