What is the surface area?

Question

17 mm 15mm 8mm 9mm. the figure is a triangular prism.

Answer 1

In order to get the area of a triangle without an angle:

a=8

b=15

c=17

γ=acos((a^2+b^2-c^2)/(2ab))

" ((64+225-289)/(240))

" 0 (γ=90°)

This is a rt triangle. So a*b/2*9=540cu/mm

Area=ab+9a+9b+9c

or ab+9abc=18,480sq/mm