Question

two angles of a quadrilateral measure 80 degree and 70 degree the other two angles are equal. find the measure of each of the equal angles

Answer 1

let vertex of quadrilateral a,b,c,d
where a=80°and b=70°
and c=d
SO,sum of all interior angle of quadrilaral=360
a+b+c+d=360
80+70+c+d=360
150+c+c=360 (c=d)
2c=360-150
2c=210
c=210÷2
c=105
c=d=105
means
c=105
d=105