He sold 12 coins, 16+28+32+4=80. 15% of 80 is 12
Add 8 to 46. Then divide 54/8 to get 6.75 and t=6.75
For the 51-deg angle, y is the opposite leg, and 12 is the hypotenuse.
The trig ratio that relates the opposite leg and the hypotenuse is the sine.
sin A = opp/hyp
sin 51 deg = y/12
y = 12 * sin 51 deg
y = 9.3