Question

in ∆ABC,<C=3<B=2(<A+<B) then the value of <B will be?​

Answer 1

$To\:find \: \angle c \: we \: have \: to \: find \: \angle \: A\:and\: \angle \: B\:as\:well$

$C\:=\:2\:(A\:+B)$

$C\:=\:3B\:or$

$2(A+B)\:=\:3B\:or$

$2A\:+2B\:=\:3B\:or$

$B\:=2A$

$C\:=\:2(A\:+\:2A) = 6A$

$A+2A+6A\:=\:6A$

$A+2A+6A\:=\:180\:or\:9A\:=\:180.$

$Or\:A\:=\: {20}^{o}$

$B\:=\: {40}^{o}$

$C\:=\: {120}^{o}$