Question 17 of 17

A right cone has a slant height of 17 feet, and the diameter of the base is 30 feet. What is the height, [tex]h[/tex], of the cone?

A. 8 ft
B. [tex]\sqrt{514}[/tex] ft
C. 13 ft
D. 64 ft



Answer :

To determine the height [tex]\( h \)[/tex] of the right cone, we'll use the Pythagorean Theorem. Here are the steps:

1. Understand the Given Data:
- The slant height [tex]\( l \)[/tex] of the cone is [tex]\( 17 \)[/tex] feet.
- The diameter of the base of the cone is [tex]\( 30 \)[/tex] feet.

2. Determine the Radius of the Base:
- The radius [tex]\( r \)[/tex] can be found by dividing the diameter by 2.
[tex]\[ r = \frac{30}{2} = 15 \text{ feet} \][/tex]

3. Apply the Pythagorean Theorem:
- In a right cone, the slant height [tex]\( l \)[/tex], the radius [tex]\( r \)[/tex], and the height [tex]\( h \)[/tex] form a right triangle.
- The Pythagorean Theorem states that:
[tex]\[ l^2 = r^2 + h^2 \][/tex]
- Substitute the known values:
[tex]\[ 17^2 = 15^2 + h^2 \][/tex]

4. Simplify and Solve for [tex]\( h \)[/tex]:
- Calculate [tex]\( 17^2 \)[/tex] and [tex]\( 15^2 \)[/tex]:
[tex]\[ 17^2 = 289 \][/tex]
[tex]\[ 15^2 = 225 \][/tex]
- Substitute these values back into the equation:
[tex]\[ 289 = 225 + h^2 \][/tex]
- Isolate [tex]\( h^2 \)[/tex] by subtracting 225 from both sides:
[tex]\[ h^2 = 289 - 225 \][/tex]
- Simplify the right side:
[tex]\[ h^2 = 64 \][/tex]
- Take the square root of both sides to solve for [tex]\( h \)[/tex]:
[tex]\[ h = \sqrt{64} \][/tex]
- Therefore,
[tex]\[ h = 8 \text{ feet} \][/tex]

Thus, the height [tex]\( h \)[/tex] of the cone is [tex]\( 8 \)[/tex] feet. The correct answer is:

A. [tex]\( 8 \text{ ft} \)[/tex]