One angle of a non-regular quadrilateral is a right angle. The largest angle is 3 times the size of the smallest angle. The fourth angle is 15 degrees greater than the smallest. What is the measure, in degrees, of the largest angle?
quadrilaterals have a sum of the angles equaling 360
one angle is 90, the smallest is x, the largest is 3x, and the fourth is x+15
105+5x=360
x=51
thus the largest angle is 153
+1347 
