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McGraw Hill Integrated II, 2012

MH

McGraw Hill Integrated II, 2012 View details

Study Guide and Review

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Exercise 21 Page 325

What does the angle marker mean on the diagram?

90^(∘)

Practice makes perfect

The red angle marker on the diagram indicates that the two lines forming that angle are perpendicular.

According to Right Angle Theorem 2.9, perpendicular lines form four right angles. So ∠ 5 is a right angle, which means that m∠ 5=90^(∘).

Subchapter links

1 Postulates and Paragraph Proofs p.324

2 Algebraic Proof p.324

3 Proving Segment Relationships p.325

4 Proving Angle Relationships p.325

5 Angle and Parallel Lines p.326

6 Proving Lines Parallel p.326