Question

use angle addition postulate to answer 7. m∠bcv = 120° and m∠bcd = 177°. find m∠vcd.

Explanation:

Step1: Recall angle - addition postulate

By the angle - addition postulate, $m\angle BCD=m\angle BCV + m\angle VCD$.

Step2: Solve for $m\angle VCD$

We can rewrite the formula as $m\angle VCD=m\angle BCD - m\angle BCV$.
Substitute $m\angle BCD = 177^{\circ}$ and $m\angle BCV=120^{\circ}$ into the formula: $m\angle VCD=177^{\circ}- 120^{\circ}$.
$m\angle VCD = 57^{\circ}$

Answer:

$57^{\circ}$