Question

In the figure, AB=AC and Angle ACD is equal to 120,find Angle B

Answer 1

this is your answer

Answer 2

$In \: \triangle ABC, \\AB = AC \implies \angle B = \angle C$

$\blue { ( Angles \: opposite \: to \: equal \: sides } \\\blue { are \: equal ) }$

$\angle {ACD} = 120\degree \:(given)$

$\angle {ACB} + \angle {ACD} = 180\degree\: ( Linear \:pair )$

$\implies \angle {ACB} + 120 \degree = 180\degree$

$\implies \angle {ACB} = 180 \degree - 120\degree$

$\implies \angle {ACB} = 60\degree$

$\angle B = \angle {ACB} = 60\degree$

Therefore.,

$\red { \Angle B } \green {= 60\degree}$

•••♪