Big Ideas Math: Modeling Real Life, Grade 8
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Big Ideas Math: Modeling Real Life, Grade 8 View details
1. Parallel Lines and Transversals
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Exercise 10 Page 108

Use the relationship of angles between parallel lines.

Angle Measures: ∠5 = 49^(∘), ∠6=131^(∘)
Explanation: See solution.

Practice makes perfect

Let's consider the given diagram.

angles
To find the measure of ∠ 5, we will use the fact that corresponding angles of parallel lines are congruent. Since the 49^(∘) angle and ∠ 5 are corresponding angles and lines a and b are parallel, these angles are congruent.
angles

Congruent angles have the same measure, so the measure of ∠ 5 is 49^(∘). Finally, note that ∠ 5 and ∠ 6 form a straight line.

angles

Therefore, they are supplementary and the sum of their measures is 180^(∘). With this information, we can finally find the measure of ∠ 6. m∠ 6+ 49^(∘)=180^(∘) ⇕ m∠ 6=131^(∘)