Understanding Exterior Angle Theorem
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Beginner
Start here! Easy to understand
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Beginner Explanation
The measure of an exterior angle is the sum of the two opposite interior angles: $m \angle 4 = m \angle 1 + m \angle 2$.
Practice Problems
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1
Quick Quiz
Single Choice Quiz
Beginner
In triangle ABC, where $$\angle 1$$ is at vertex A, $$\angle 2$$ at vertex B, $$\angle 3$$ at vertex C, and $$\angle 4$$ is the exterior angle at vertex C: If $m \angle 1 = 40^\circ$ and $m \angle 2 = 50^\circ$, what is $m \angle 4$?
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2
Real-World Problem
Question Exercise
Intermediate
Teenager Scenario
Imagine a triangle-shaped park with an exterior walkway forming an angle. If one interior angle is $35^\circ$ and another is $45^\circ$, find the measure of the walkway's exterior angle.
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3
Thinking Challenge
Thinking Exercise
Intermediate
Think About This
In triangle ABC, where $$\angle 1$$ at vertex A equals $x^\circ$, $$\angle 2$$ at vertex B equals $(x + 10)^\circ$, and $$\angle 4$$ is the exterior angle at vertex C, find $m \angle 4$ in terms of x.
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4
Challenge Quiz
Single Choice Quiz
Advanced
In triangle ABC, where $$\angle 1$$ is at vertex A, $$\angle 2$$ at vertex B, $$\angle 3$$ at vertex C, and $$\angle 4$$ is the exterior angle at vertex C: If $m \angle 1 = 2x^\circ$ and $m \angle 2 = (3x - 10)^\circ$, what is $m \angle 4$?
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Recap
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