Question

ing other measures
drag a vertex of the triangle to change its shape.
double - click or double - tap a vertex or side to prevent
it from changing.
reset
if the measure of ∠b is 40°, what measures can ∠a and ∠c be? choose
three correct answers.
□ 55° and 85°
□ 30° and 110°
□ 60° and 90°
□ 20° and 30°
□ 70° and 70°

Explanation:

Step1: Recall triangle angle sum

The sum of angles in a triangle is \(180^\circ\). Given \(\angle B = 40^\circ\), so \(\angle A+\angle C=180 - 40=140^\circ\).

Step2: Check each option

• For \(55^\circ\) and \(85^\circ\): \(55 + 85=140\), valid.
• For \(30^\circ\) and \(110^\circ\): \(30 + 110 = 140\), valid.
• For \(60^\circ\) and \(90^\circ\): \(60+90 = 150

eq140\), invalid.

• For \(20^\circ\) and \(30^\circ\): \(20 + 30=50

eq140\), invalid.

• For \(70^\circ\) and \(70^\circ\): \(70+70 = 140\), valid.

Answer:

The correct options are:

• \(55^\circ\) and \(85^\circ\)
• \(30^\circ\) and \(110^\circ\)
• \(70^\circ\) and \(70^\circ\)