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Interior and exterior triangles

Interior and exterior triangles-example-1
User Safet
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1 Answer

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Answer:

∠ PQR = 18°

Explanation:

the exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

∠ PQR is an exterior angle of the triangle , then

∠ PQR = ∠OPQ + ∠ QOP , that is

4x - 10 = x + 9 + x - 5

4x - 10 = 2x + 4 ( subtract 2x from both sides )

2x - 10 = 4 ( add 10 to both sides )

2x = 14 ( divide both sides by 2 )

x = 7

Then

∠ PQR = 4x - 10 = 4(7) - 10 = 28 - 10 = 18°

User Jspcal
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