I only did the first part but maybe later I will solve the rest too. If there are any errors but tell me so I can update the pic.
18.84
Since the formula of circumference is C = 2 pi r or C = pi times diameter, you can conclude that the circumference is 18.84.
Assuming that pi is 3.14 in this case rather than the full pi or just in terms of pi.
Hope this helps!
Given:
A prism with right triangular base.
Base of triangle = 6 ft
Height of triangle = 8 ft
Height of prism = 7
To find:
The volume of the given prism.
Solution:
The volume of prism is:
...(i)
Where, B is the base area and h is the height of the prism.
In the given figure, the base of the prism is a right angle triangle with legs 6 ft and 8 ft. So, the area of the base is:




Substituting
in (i), we get


Therefore, the volume of the prism is 168 cubic ft.