Question

BD is the angle bisector of

Answer 1

Note: Let us consider, we need to find the $m\angle ABC$ and $m\angle DBC$.

Given:

In the given figure, BD is the angle bisector of ABC.

To find:

The $m\angle ABC$ and $m\angle DBC$.

Solution:

BD is the angle bisector of ABC. So,

$m\angle ABD=m\angle DBC$

$3x=x+20$

$3x-x=20$

$2x=20$

Divide both sides by 2.

$x=\dfrac{20}{2}$

$x=10$

Now,

$m\angle DBC=(x+20)^\circ$

$m\angle DBC=(10+20)^\circ$

$m\angle DBC=30^\circ$

And,

$m\angle ABC=(3x)^\circ+(x+20)^\circ$

$m\angle ABC=(4x+20)^\circ$

$m\angle ABC=(4(10)+20)^\circ$

$m\angle ABC=(40+20)^\circ$

$m\angle ABC=60^\circ$

Therefore, $m\angle DBC=30^\circ,m\angle ABD=30^\circ$ and $m\angle ABC=60^\circ$.