Help! This is from my geometry work!

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

The cross-sectional areas of a right triangular prism and a right cylinder are congruent. the right triangular prism has a height of 6 units, and the right cylinder has a height of 6 units. which conclusion can be made from the given information? the volume of the triangular prism is half the volume of the cylinder. the volume of the triangular prism is twice the volume of the cylinder. the volume of the triangular prism is equal to the volume of the cylinder. the volume of the triangular prism is not equal to the volume of the cylinder.

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ac=26 and ch=8, find bh.