Statements
1
Quadrilateral ABCDwith m/A= (10z), m/B= (8x), m/C= (10z)",
and m/D= (8x)".
2 m/A+m/B+m/C+m/D=360°
3 (10x)+(8x) + (10x) + (8x) = 360°
4
5 x=10
Reasons
Given
Substitution Property
Combine like terms