Question

the two adjacent angles of a quadrilateral are 80 and 120 the other two angles are equal. find them

Answer 1

let the angles be a,b,c and d.
given,
let a=80
b=120
c=d
a+b+c+d=360(angle sum property)
120+80+c+d=360
200+2c=360(c=d)
2c=360-200
c=160/2
c=80
Hence,c=d=80

Answer 2

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Sum of angles of quadrilateral=360°
Two adjacent angles are=80° and 120°
=200°
Then sum of remaining angles = 360°-200°
=160°
Since , the angles are equal
160°/2=80°

So , the other angles are 80° and 80°

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