McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
4. Trigonometry
Continue to next subchapter

Exercise 34 Page 656

Create an equation using the definition of the sine of an angle.

≈ 24 in.

Practice makes perfect

Let's begin with recalling the definition of the sine of an angle. If△ ABCis a right triangle with acute∠ A, then the sine of∠ Ais the ratio of the length of the leg opposite∠ Ato the length of the hypotenuse.

Now let's look at the given picture. We are given that the springboard Eric uses in his gymnastic class has 6-inch coils and forms an angle of 14.5^(∘) with the base. Let l represents the length of the springboard. We will assume that the coils are perpendicular to the base.

Next we can write that the sine of 14.5^(∘) is the ratio of the length of the opposite leg, 6, to the length of the hypotenuse, l. sin 14.5^(∘)=6/l We can solve for l by evaluating sin 14.5^(∘) using a calculator.
sin 14.5^(∘)=6/l
Solve for l
l*sin14.5^(∘)=6
l=6/sin14.5^(∘)
l=23.9635...
l≈24
The springboard is about 24 inches.