First we should figure out the volume of the prism (ignoring the cylinder at the moment)
(base * height/2)*depth
We need to find the height of the triangle which can be done with pythagoras because this is a right angled triangle (as shown by the little square at the bottom)
12 is the hypotenuse.
√12²-10² =6.63 (rounded)
Now we have the height of the triangle and can find the volume.
12*6.63/2*15=596.7
Now we find the volume of the cylinder.
area of circle * depth
area=3.14*1.5²
3.14*2.25
7.065
7.065*15=105.975
Now we subtract the volume of the cylinder from the volume of the prism and you have:
596.7-105.975
490.725 which is your answer
Hope this helps :)
