Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
3. Right Triangles and Trigonometric Ratios
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Exercise 24 Page 924

Use the sine ratio to find m ∠ A.

b≈ 14.0
m ∠ A ≈ 50.6^(∘)
m ∠ B ≈ 39.4^(∘)

Practice makes perfect

First, let's draw the measurements from the exercise on a right triangle to visualize the given information.

We will find the missing measures one at a time. In this case, this means that we want to find m ∠ A, m ∠ B, and b.

Angle Measures

We can find m ∠ A using a sine ratio. The sine of ∠ A is the ratio of the length of the leg opposite ∠ A to the length of hypotenuse. sin A=Opposite/Hypotenuse ⇒ sin A =17/22 By the definition of the inverse sine, the inverse sine of 1722 is the measure of ∠ A. To find it, we have to use a calculator.
m∠ A=sin ^(-1) 17/22
m∠ A = 50.59943... ^(∘)
m∠ A ≈ 50.6 ^(∘)
To find m∠ B, recall that the acute angles of a right triangle are complementary. Therefore, m ∠ A and m ∠ B add up to 90^(∘). m ∠ A + m ∠ B = 90^(∘) Now, we can substitute the measure of ∠ A in our equation and find the measure of ∠ B. 50.6 ^(∘)+ m ∠ B ≈ 90^(∘) ⇔ m ∠ B ≈39.4^(∘)

Side Lengths

Finally, we can find the measure of b. To do it, we can use the Pythagorean Theorem. a^2 + b^2 = c^2 Let's substitute the known lengths, a= 17 and c= 22, into this equation to find b.
a^2+b^2=c^2
17^2+b^2= 22^2
Solve for c
289+b^2=484
b^2=195
b=sqrt(195)
b=13.964240...
b≈ 14.0