Konery wants to make their waffle cones with a height of 6 in. Their current net design has a diameter of 2.5 in. and a slant height of 6.25 in. Will this work for the desired height? Round the answer to the nearest tenth.(1 point)

Responses

No; the height is too long by 0.7 in. 
No; the height is too long by 0.7 in. 

No; the height is too short by 0.3 in.
No; the height is too short by 0.3 in.

No; the height is too long by 0.1 in.
No; the height is too long by 0.1 in.

No; the height is too long by 0.4 in.

1 answer

To determine whether the waffle cone design will work for the desired height, we can use the relationship between the slant height, the radius of the base, and the height of a cone.

The slant height (l), height (h), and radius (r) of a cone are related by the Pythagorean theorem:

\[ l^2 = r^2 + h^2 \]

Given:

  • Slant height \( l = 6.25 , \text{in} \)
  • Diameter \( d = 2.5 , \text{in} \) → Radius \( r = \frac{d}{2} = \frac{2.5}{2} = 1.25 , \text{in} \)
  • Desired height \( h = 6 , \text{in} \)

We need to find out if the height of 6 inches and the slant height of 6.25 inches create a valid cone when the radius is 1.25 inches. We can calculate the height using the equation above:

  1. Calculate \( r^2 \): \[ r^2 = (1.25)^2 = 1.5625 \]

  2. Calculate \( l^2 \): \[ l^2 = (6.25)^2 = 39.0625 \]

  3. Substitute into the Pythagorean theorem: \[ 39.0625 = 1.5625 + h^2 \]

  4. Solve for \( h^2 \): \[ h^2 = 39.0625 - 1.5625 = 37.5 \]

  5. Now calculate \( h \): \[ h = \sqrt{37.5} \approx 6.123 \]

Now we compare \( h \approx 6.123 \) inches with the desired height of 6 inches:

The height of the cone is approximately 6.1 inches, which means it is too long by:

\[ 6.123 - 6 = 0.123 \text{ inches} \]

Rounding to the nearest tenth, the cone height is too long by about 0.1 inches.

Thus, the correct response is: No; the height is too long by 0.1 in.