Chapter 12.3, Problem 9WE

To determine

To calculate: The lateral area, total area, and volume of the cone.

Answer to Problem 9WE

The l =5units, lateral area = 62.8 sq. units, total area = 113.04 sq. units, and volume = 50.24 cu. units

Explanation of Solution

Given information: Consider the given information,

Radius = 4units, Height = 3units, $\pi \approx 3.14$

Formula used: Consider the given formula,

r = radius, h = height, l = length

  $l=\sqrt{{(r)}^2+{(h)}^2}$

Lateral area = $\pi rl$

Total area = $\pi rl+\pi r^2$

Volume = $\frac{1}{3}\pi r^{2}h$

Calculation : Consider the given information the formula is,

  $l=\sqrt{{(3)}^2+{(4)}^2}=\sqrt{25}=5$ units

Lateral area = $3.14\times 4\times 3=62.8$ sq. units

Total area = $(3.14\times 4\times 3)+(3.14\times {(4)}^2)=113.04$ sq. units

Volume = $\frac{1}{3}\times 3.14\times {(4)}^2\times 3=50.24$ cu. units