Question

geometry - honors - 9(a.c)10(a) - 2025 - 2026 snapshot prep 1 use the triangle shown. if m∠1 = 98° and m∠2 = 19°, what is m∠3? m∠3 =

Explanation:

Step1: Recall angle - sum property

The sum of the interior angles of a triangle is 180°. Also, ∠1 is an exterior angle and ∠1=∠2 + ∠3 (by the exterior - angle property of a triangle, which states that an exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles).

Step2: Rearrange the formula to solve for ∠3

We can rewrite the formula ∠1=∠2 + ∠3 as ∠3=∠1−∠2.

Step3: Substitute the given values

Given ∠1 = 98° and ∠2 = 19°, we substitute these values into the formula: ∠3=98°−19°.
$m\angle3 = 79^{\circ}$

Answer:

79