Question

if angleA- angle B= 63°,angle B-angle C=18°,find angle B​

Answer 1

Answer:

$\red { \angle B }\green {= 45\degree }$

Step-by-step explanation:

$\angle A - \angle B = 63\degree$

$\implies \angle A = 63 + \angle B \: ---(1)$

$\angle B - \angle C = 18\degree$

$\implies \angle C = \angle B - 18\degree\: ---(2)$

$We \:know \: the \: Angle \:sum \: Property ,$

$\angle A + \angle B + \angle C = 180\degree$

$\implies 63 \degree + \angle B + \angle B + \angle B - 18\degree = 180\degree \: [ From \: (1)\:and \:(2) ]$

$\implies 3\angle B + 45\degree = 180\degree$

$\implies 3\angle B = - 45\degree + 180\degree\\= 135\degree$

$\implies \angle B= \frac{135}{3} = 45\degree$

Therefore.,

$\red { \angle B }\green {= 45\degree }$

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