The sum of the interior angles in a triangle is always 180°.
If Angle B is 40°, we can determine the possible measures for Angle A and Angle C by using the equation:
Angle A + Angle B + Angle C = 180°
Substituting the value of Angle B:
Angle A + 40° + Angle C = 180° Angle A + Angle C = 180° - 40° Angle A + Angle C = 140°
Now we can evaluate the proposed pairs:
-
20° and 30°:
- 20° + 30° = 50° (not valid)
-
30° and 110°:
- 30° + 110° = 140° (valid)
-
55° and 85°:
- 55° + 85° = 140° (valid)
-
60° and 90°:
- 60° + 90° = 150° (not valid)
-
70° and 70°:
- 70° + 70° = 140° (valid)
The three correct measures for Angle A and Angle C are:
- 30° and 110°
- 55° and 85°
- 70° and 70°