Question

Justify each statement with a property from algebra or property of congruence.

If$m\angle A+m\angle B+50=180$and $m\angle C=50$, then $m\angle A+m\angle B+50=180$.

Short answer

From the property of Algebra, it is proved that $m\angle A+m\angle B+50=180$.

Step-by-step solution

Step 1. Apply substitution property of algebra.

If$a=b$ then a can be substituted for b or b can be substituted for a.

Step 2. Description of step.

The sum of measures of all the interior angles of a triangle is 180.

$m\angle A+m\angle B+m\angle C=180$

Step 3. Description of step.

Substitute 50 form∠Cinto the relation given in step 2.

$m\angle A+m\angle B+50=180$

Therefore, it is proved that $m\angle A+m\angle B+50=180$.