Use the image to answer the question.

An illustration shows a cylinder resting on its bottom base. The top base is visible. The part of the bottom base that is not visible is indicated by a dashed line. Parts of the cylinder are labeled. A large black point is shown in the center of the top face of the cylinder. A solid line extends from that point to the edge of the cylinder and is labeled r indicating the radius. The vertical line on the right side of the cylinder is labeled h. On the interior of the cylinder, a dotted line extends diagonally from top right to bottom left from where the radius line meets the edge down to the opposite side of the cylinder where the other face meets the edge. This line is labeled d.

Find the height, h, of the cylinder. The radius, r, is 5 cm and the diagonal, d, is 15 cm. Round the answer to the nearest tenth.

(1 point)
Responses

11.2 cm
11.2 cm

15.8 cm
15.8 cm

14.1 cm
14.1 cm

18.0 cm

1 answer

To find the height \( h \) of the cylinder using the given radius \( r = 5 \) cm and the diagonal \( d = 15 \) cm, we can use the Pythagorean theorem.

In a cylinder, when you draw a diagonal \( d \) from the top edge to the opposite bottom edge while having a vertical height \( h \) and the radius \( r \) as the horizontal distance from the center to the edge, you form a right triangle. The relationship can be expressed as:

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

Given:

  • \( r = 5 \) cm
  • \( d = 15 \) cm

Substituting these values into the equation:

\[ 15^2 = h^2 + 5^2 \]

Calculating the squares:

\[ 225 = h^2 + 25 \]

Now, solve for \( h^2 \):

\[ h^2 = 225 - 25 \] \[ h^2 = 200 \]

Taking the square root of both sides to find \( h \):

\[ h = \sqrt{200} = \sqrt{100 \cdot 2} = 10\sqrt{2} \approx 14.14 \]

Rounding to the nearest tenth, we get:

\[ h \approx 14.1 \text{ cm} \]

Thus, the height \( h \) of the cylinder is:

14.1 cm