Since it’s a trapezoid, 111 + b will equal 180, as will 41 + a.
111 + b = 180 means b = 69.
41 + a = 180 means a = 139.
This happens simply because two angles that are positioned that way between parallel lines will always be supplementary. It’s also worth noting that all angles in any quadrilateral will add up to be 360 degrees.
7ft = 84in 84 ÷ 15 = 5.6 pieces he can cut from each board. Since .6 is not a whole piece measuring 15 inches long, he can only cut 5 pieces from each board.
So, 5 x 2 = 10
He would be able to cut 10 pieces measuring 15 inches long.