Question

A solar panel a = 12 feet in width, which is to be attached to a roof that makes an angle of 25° with the horizontal. The bottom edge of the solar panel makes contact with the roof. The top edge of the solar panel is elevated above the roof by a vertical brace of length d. Approximate the length d (in feet) of the vertical brace that is needed for the panel to make an angle of 45° with the horizontal.

Answer 1

angle D = 45 - 25 = 20 degrees
call point B at the very top of the panel
then the angle at B = 180 - 90 - 45 = 45 degrees
then the last angle between the roof and your holding pole is
180 -45 - 20 = 115 degrees
then
sin 20 / d = sin 115 /12