Answer:
400 ft³
Step-by-step explanation:
The volume of a square pyramid can be calculated as:
![V=(1)/(3)a^2h](https://img.qammunity.org/2023/formulas/mathematics/college/gbm3ovdgq35kgynx3enkm29x11e8mi85iy.png)
Where a is the side of the square and h is the height of the pyramid.
Now, we need to calculate the height using the slant height, so we will use the following equation:
![h=\sqrt[]{s^2-(a^2)/(4)}](https://img.qammunity.org/2023/formulas/mathematics/college/r53qgdbe2yvd02ew6z5h1n781awixi0sde.png)
So, the height of the pyramid is equal to:
![\begin{gathered} h=\sqrt[]{13^2-(10^2)/(4)} \\ h=\sqrt[]{169-(100)/(4)} \\ h=\sqrt[]{169-25} \\ h=\sqrt[]{144} \\ h=12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2z1pvg7xotseo673q5j3kx6yjy4giesrhq.png)
Then, the volume of the square pyramid is equal to:
![\begin{gathered} V=(1)/(3)(10)^2(12) \\ V=(1)/(3)(100)(12) \\ V=400 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/4bic3oor63kp8kt726sz7p13wbhpszl5wn.png)
Therefore, the answer is 400 ft³