Question 911466:  Please help me solve this question tried my best but couldn't answer it!  
 Question: In quadrilateral ABCD, m/A=(x-10), m/B=(2x+10), m/C=(2x-70) m/D(3x-50).What kind of quadrilateral ia ABCD? Why? 
 Answer by mananth(16946)      (Show Source): 
You can  put this solution on YOUR website! In quadrilateral ABCD, m/A=(x-10), m/B=(2x+10), m/C=(2x-70) m/D(3x-50)
 
Sum of angles of quadrilateral = 360 deg
 
(x-10)+(2x+10)+(2x-70)+(3x-50)=360
 
8x-120=360 
6x=360+120 
8x=480
 
x=60
 
 m/A=(x-10),=50 
 m/B=(2x+10),130 
 m/C=(2x-70) 50 
m/D(3x-50)130
 
The opposite angles are equal 
Hence its a parallelogram
 
 
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