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Exterior Angle Theorem Worksheet

Grade 9 Math worksheet focusing on the Exterior Angle Theorem with various question types.

Grade 9 Math GeometryExterior Angle Theorem
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Includes

3 Short AnswerMultiple ChoiceFill in the BlanksTrue / False

Standards

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

Topics

mathgeometryexterior angle theoremtrianglesgrade 9
8 sections · Free to use · Printable
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Exterior Angle Theorem

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

1. In your own words, state the Exterior Angle Theorem.

2. The measure of an exterior angle of a triangle is equal to the sum of the measures of which two angles?

a

The two adjacent interior angles

b

The two non-adjacent interior angles

c

The sum of all three interior angles

d

None of the above

3. If an exterior angle of a triangle measures 110 degrees, and one of the remote interior angles measures 50 degrees, the other remote interior angle must measure   degrees.

4. Consider the triangle ABC. If the exterior angle at vertex C is 125 degrees, and angle A is 60 degrees, what is the measure of angle B?

ABC125°60°

5. An exterior angle of a triangle can be acute.

T

True

F

False

6. In triangle PQR, the exterior angle at Q is (3x + 10) degrees. Angle P is (x + 20) degrees and angle R is (x + 30) degrees. Find the value of x and the measure of the exterior angle at Q.