A circus tent is the shape of a square pyramid. It has a base edge of 20meter, a slant height of 13.5m. Find the height of the tent.

Round to nearest tenth.

1 answer

To find the height of a square pyramid given the slant height and the base edge, we can use the Pythagorean theorem.

First, we'll denote:

  • The height of the tent (pyramid) as \( h \).
  • The base edge of the pyramid as \( s = 20 \) meters.
  • The slant height as \( l = 13.5 \) meters.

In a square pyramid, the vertical height \( h \), the slant height \( l \), and half the length of the base edge \( \frac{s}{2} \) form a right triangle. The relationship can be expressed as follows:

\[ l^2 = h^2 + \left(\frac{s}{2}\right)^2 \]

First, calculate \( \frac{s}{2} \):

\[ \frac{s}{2} = \frac{20}{2} = 10 \text{ meters} \]

Now substitute \( l \) and \( \frac{s}{2} \) into the Pythagorean theorem equation:

\[ (13.5)^2 = h^2 + (10)^2 \]

Calculating \( (10)^2 \) and \( (13.5)^2 \):

\[ (10)^2 = 100 \] \[ (13.5)^2 = 182.25 \]

Substituting back into the equation:

\[ 182.25 = h^2 + 100 \]

Now, isolate \( h^2 \):

\[ h^2 = 182.25 - 100 = 82.25 \]

Taking the square root to find \( h \):

\[ h = \sqrt{82.25} \approx 9.1 \text{ meters} \]

Thus, the height of the tent is approximately 9.1 meters when rounded to the nearest tenth.