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 52 Page 594

Before you can find y^(∘) you have to find x^(∘).

x^(∘)=26^(∘)
y^(∘)=64^(∘)

Practice makes perfect

According to the Corollary to the Triangle Sum Theorem, the acute angles of a right triangle are complementary. Therefore, we can write the equation x^(∘)+64^(∘)=90^(∘) Let's solve this equation.

x^(∘)+64^(∘)=90^(∘)
x^(∘)=26^(∘)
When we know the measure of x^(∘), we can use this information to find the alternate interior angle which we have highlighted and labeled as z in the figure below.

According to the Alternate Interior Angles Theorem, if two parallel lines are cut by a transversal, then the pair of alternate interior angles are congruent. Therefore, we can say that z^(∘)=26^(∘). To find the measure of y^(∘), we can use the Corollary to the Triangle Sum Theorem which states that the acute angles of a right triangle are complementary. Therefore, we can write the following equation y^(∘)+26^(∘) = 90^(∘). Let's solve this equation.

y^(∘)+26^(∘) = 90^(∘)
y^(∘)= 64^(∘)

The measure of y is 64^(∘).