Koney 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.

No, the height is too long by 0.1 in
No, the height is too short by 0.3 in
No, the height is too long by 0.4 in
No, the height is too long by 0.7 in

1 answer

To determine if Koney's current net design will work for the desired height, we can use the geometry of a cone.

We have:

  • Diameter of the base (d) = 2.5 in
  • Radius (r) = d/2 = 2.5 in / 2 = 1.25 in
  • Slant height (l) = 6.25 in
  • Desired height (h) = 6 in

To find the actual height of the cone from the given slant height and radius, we can use the Pythagorean theorem. The relationship is:

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

Now, we can plug in the known values:

\[ 6.25^2 = h^2 + 1.25^2 \] \[ 39.0625 = h^2 + 1.5625 \] Subtract \(1.5625\) from both sides:

\[ 39.0625 - 1.5625 = h^2 \] \[ 37.5 = h^2 \] Now take the square root of both sides:

\[ h = \sqrt{37.5} \approx 6.123 \]

Now, we can compare this calculated height to the desired height of 6 inches:

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

Since we are rounding to the nearest tenth, this shows that the height is too long by approximately 0.1 inches.

Thus, the answer is:

No, the height is too long by 0.1 in.