Question

if m∠abd = 70° and m∠cbd = 30°, then m∠abc = ?°

Explanation:

Step1: Identify angle - relationship

We know that $\angle ABC=\angle ABD-\angle CBD$.

Step2: Substitute given values

Given $\angle ABD = 70^{\circ}$ and $\angle CBD=30^{\circ}$, so $\angle ABC=70^{\circ}- 30^{\circ}$.

Step3: Calculate the result

$70 - 30=40$.

Answer:

$40$