Triangle Sum Theorem Worksheet
This worksheet focuses on applying the Triangle Sum Theorem to find missing angles in triangles for Grade 9 students.
Includes
Standards
Topics
Triangle Sum Theorem
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Read each question carefully and use the Triangle Sum Theorem to find the missing angle(s). Show all your work.
1. In triangle ABC, if angle A = 60° and angle B = 75°, what is the measure of angle C?
2. A triangle has angles measuring 3x, 2x, and 40°. Find the value of x and the measure of each angle.
1. The sum of the interior angles of any triangle is always 180°.
True
False
2. An obtuse triangle can have two obtuse angles.
True
False
1. If two angles of a triangle are 50° and 80°, what is the measure of the third angle?
30°
50°
70°
90°
2. Which of the following angle combinations can form a triangle?
40°, 60°, 90°
50°, 50°, 50°
70°, 70°, 40°
All of the above
1. The Triangle Sum Theorem states that the sum of the measures of the interior angles of a triangle is always .
2. If a triangle has angles measuring 90° and 35°, the third angle must measure .
1. Consider a triangle where the angles are in the ratio 1:2:3. Find the measure of each angle.
2. An isosceles triangle has one angle measuring 100°. What are the measures of the other two angles?