#2:

Find the equation of your parabola. The vertex is at (0,32)

and it passes through (42,0)

y=a(x-h)^2+k

0=a(42-0)^2+32

a=-8/441

The parabola equation is y=-8x^2/441+32

Can you continue from there?. We centered the parabola at the origin.

Space your beams accordingly. You could put the first one to the right at x=6, then x=18, then x=30.

The same to the left. Add up all your y values.