The sum of the four angle measures of any convex quadrilateral is360

Question

The sum of the four angle measures of any convex quadrilateral is360 degrees. Suppose that a convex quadrilateral has angle measures of 60,10y-9 , and 9y-7 degrees. Write an expression for the degree measure of the fourth angle.

Answer 1

F = fourth angle

 

F = 360 - 60 - (10y - 9) - (9y - 7)

F = 300 - 10y + 9 - 9y + 7

F = 300 - 19y + 16

F = 316 - 19y