Question

(vii) part. Find x using suitable properties of s triangle class 7

Answer 1

angle of the straight line is 180°
180-120= 60°

2 sides are equal. therefore 2 angles are also equal
x=60°

Answer 2

$\: \bold{Sum \: of \: all \: angles \: on \: a \: straight \: line \: on \: a \: particular \: point = 180°} \\ \\ \\ \bold{ Angle \: adjacent \: to \: 120° + 120° = 180°} \\ \\ \bold{ => angle \: adjacent \: to \: 120° = 180° - 120°} \\ \\ => angle \: adjacent \: to \: 120° = 60°$



Hence,


$\mathbf{ \angle x =adjacent \: angle \: to \: 120 \degree \: = 60 \degree} \: \: \: \: \: \: \: \: \: ( \: by \: the \: property \: of \: isosceles \: triangles\: )$