A cone has a height of 16 centimeters and a radius of 12 centimeters. What is the exact lateral and surface area of the cone?

Type the correct answer in each box. Use numerals instead of words.

The lateral area is ______ square centimeters.

The total surface area is ______ square centimeters.



Answer :

Certainly! Let's break down the problem and find the appropriate areas step-by-step.

1. Height and Radius of the Cone:
- The given height (h) of the cone is 16 centimeters.
- The given radius (r) of the base of the cone is 12 centimeters.

2. Slant Height Calculation:
- First, we need to determine the slant height [tex]\( l \)[/tex] of the cone. To do this, we use the Pythagorean theorem:
[tex]\[ l = \sqrt{h^2 + r^2} \][/tex]
- Substituting the given values:
[tex]\[ l = \sqrt{16^2 + 12^2} \][/tex]
[tex]\[ l = \sqrt{256 + 144} \][/tex]
[tex]\[ l = \sqrt{400} \][/tex]
Thus, the slant height [tex]\( l \)[/tex] is 20 centimeters.

3. Lateral Area Calculation:
- The formula for the lateral (or curved) surface area [tex]\( A_L \)[/tex] of a cone is:
[tex]\[ A_L = \pi r l \][/tex]
- Substituting the values:
[tex]\[ A_L = \pi \times 12 \times 20 \][/tex]
- Therefore, the lateral area [tex]\( A_L \)[/tex] is approximately 753.98 square centimeters.

4. Base Area Calculation:
- The base area [tex]\( A_B \)[/tex] of the cone is found using the formula for the area of a circle:
[tex]\[ A_B = \pi r^2 \][/tex]
- Substituting the values:
[tex]\[ A_B = \pi \times 12^2 \][/tex]
[tex]\[ A_B = \pi \times 144 \][/tex]
- Therefore, the base area [tex]\( A_B \)[/tex] is approximately 452.39 square centimeters.

5. Total Surface Area Calculation:
- The total surface area [tex]\( A_T \)[/tex] of the cone is the sum of the lateral area and the base area:
[tex]\[ A_T = A_L + A_B \][/tex]
- Substituting the values:
[tex]\[ A_T = 753.98 + 452.39 \][/tex]
- Thus, the total surface area [tex]\( A_T \)[/tex] is approximately 1206.37 square centimeters.

Therefore:
- The lateral area of the cone is 753.98 square centimeters.
- The total surface area of the cone is 1206.37 square centimeters.