We know that the side L of the base of the pyramid is 20.6 in.
We also know that the slant height S is 91.1 in.
We have to find the height of the pyramid.
We can draw a cut of the pyramid, as if we were seeing it from one of the faces:
Then, we can apply the Pythagorean theorem to find H:
![\begin{gathered} H^2+((L)/(2))^2=S^2 \\ H^2=S^2-((L)/(2))^2 \\ H^2=91.1^2-((20.6)/(2))^2 \\ H^2=8299.21-11.3^2 \\ H^2=8299.21-127.69 \\ H^2=8171.52 \\ H=\sqrt[]{8171.52} \\ H\approx90.4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1fi8wn8dyyv9586w1ochy9gykujo3tvfxf.png)
Answer: The height of the pyramid is 90.4 in.