Which sentence best describe multiples of 5

Can someone me with this problem . show your work .

Find the solutions for a triangle with a =16, c =12, and b = 63º

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882