Triangle Sum Theorem Worksheet

Practice problems for understanding and applying the Triangle Sum Theorem, including finding missing angles and solving algebraic problems.

Grade 10 Math GeometryTriangle Sum Theorem

Use This Worksheet

Includes

Fill in the Blanks2 Short AnswerMultiple ChoiceTrue / FalseLong Answer

Standards

CCSS.MATH.CONTENT.HSG.CO.C.10

Topics

geometrytrianglesanglesmathgrade 10

8 sections · Free to use · Printable

Triangle Sum Theorem

Name:

Date:

Score:

Read each question carefully and answer to the best of your ability. Show all your work for full credit.

1. The sum of the interior angles of any triangle is always equal to degrees.

2. An triangle has all three angles equal, each measuring 60 degrees.

3. In triangle ABC, if angle A = 45° and angle B = 75°, what is the measure of angle C?

4. Find the value of x in the triangle below.

5. A triangle has angles measuring (2x)°, (3x - 10)°, and (x + 40)°. What is the value of x?

6. An isosceles triangle has one angle measuring 100°. What are the measures of the other two angles?

7. The angles of a triangle are in the ratio 1:2:3. Find the measure of each angle.

8. A triangle can have two obtuse angles.

True

False

9. An equilateral triangle is also an acute triangle.

True

False

10. In a right-angled triangle, one acute angle is four times the other acute angle. Find the measure of all three angles.