Question

Solve for x

Answer 1

quadrilaterals equal 360 degrees so add them all up and find out how many degrees you are missing

Answer 2

@precal is there like a formula ?

Answer 3

sum of all angles of a quadrilateral = 360
75+80+55+25x=360
25x=360-210
25x=150
x=150/25 = 6

Answer 4

Thank Yu

Answer 5

your welcome:

Answer 6

well this is how I remember it.
triangle equals 180 degrees

Answer 7

so a quadrilateral is really 2 triangles connected. There is a formula for the sum of the interior angles of any polygon

Answer 8

http://www.regentsprep.org/Regents/math/geometry/GG3/LPoly1.htm

Answer 9

180(n-2)
n is the number of sides