Given: ΔABC m∠1=m∠2
D∈
AC
, BD = DC
m∠BDC = 100°
Find: m∠A, m∠B, m∠C

, and

Step-by-step explanation:

We  are given that BD = DC

BD= DC

So, (Opposite angles of equal sides are equal) ----1

We are given that ∠BDC = 100°

In ΔBDC

Angle sum property of triangle : The sum of all angles of triangle is 180°

So,

(Using 1)

So,

We are given that

So,

Now(Linear pair)

In ΔABD

(Angle sum property)

So,

Hence , and

70

step-by-step explanation: