Explanation:
Q1. By linear pair, I know that 72* + unknown angle = 180*
therefore unknown angle = 180-72 = 108*
Now because this is a pentagon, the total of all interior angles of a polygon equals 540*
so 108* + 100* + 110* + 45* (Half of 90 , written as a semi-square) + Y* = 540
Y* = 540 - 363 = 177*
Q2. 360 - (80+70+110) = q
q = 360 - 220 = 140*
Q3. 160+160+ S* = 360*
360* - 320* = S*
S* = 40*
Hope it helps