Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
1. Angles of Triangles
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Exercise 28 Page 593

How does an exterior angle of a triangle relate to the triangles two nonadjacent interior angles?

m∠ 1=130^(∘)
Explanation: See solution

Practice makes perfect
According to the Exterior Angle Theorem, the measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. In this case, the two nonadjacent angles have been added to ∠ 1 and then equated with 180^(∘). What we instead want to do is to equate ∠ 1 with the sum of 80^(∘) and 50^(∘): m∠ 1=80^(∘)+50^(∘) By solving this equation, we can find m∠ 1.
m∠ 1=80^(∘)+50^(∘)
m∠ 1=130^(∘)
The measure of ∠ 1 is 130^(∘).