It is important to recognize that the bleacher, the ground, and the support form a right triangle with the right angle formed by the intersection of the bleacher wall and the ground. We know the bottom of the support should only be 3ft from the bleacher wall on the ground and the bleacher wall is 10ft high. We will use the Pythagorean Theorem to solve for the length of the support, which is the hypotenuse of this right triangle. Our base of the triangle is 3 feet and the leg is 10 feet.

And so we need a support of 10.44 feet long.

We begin with our original equation:

(Pythagorean Identity)

Looking at the unit circle we see that at and . We must plug these back into our original equation to validate them.

Checking

Checking

And so our only solution is

To convert radians to degrees, we need to multiply the given radians by .

The domain of a function is the range of all possible inputs, or x-values, that yield a real value for f(x). Trigonometric functions are equal to 0, 1, -1 or undefined when the angle lies on an axis, meaning that the angle is equal to 0, 90, 180 or 270 degrees (0, (pi)/2, pi or 3(pi)/2 in radians.) Trigonometric functions are undefined when they represent fractions with denominators equal to zero. Sine is defined as the ratio between the side length opposite to the angle in question and the hypotenuse (SOH, or sin x = opposite/hypotenuse). In any triangle created by the angle x and the x-axis, the hypotenuse is a nonzero number. As a result, the denominator of the fraction created by the definition sin x = opposite/hypotenuse is not equal to zero for any angle value x. Therefore, the domain of f(x) = sin x is all real numbers.

The first step to simplifying is to remember an important trig identity.

If we rewrite it to look like the denominator, it is.

Now we can substitute this in the denominator.

Now write each term separately.

Remember the following identities.

Now simplify, and combine each term.

In order to find we need to utilize the given information in the problem. We are given the opposite and adjacent sides. We can then, by definition, find the of and its measure in degrees by utilizing the function.

Now to find the measure of the angle using the function.

If you calculated the angle's measure to be then your calculator was set to radians and needs to be set on degrees.

Notice that the given information is Angle-Side-Side, which is the ambiguous case. Therefore, we should test to see if there are no triangles that satisfy, one triangle that satisfies, or two triangles that satisfy this. From , we get . In this equation, if , no that satisfies the triangle can be found. If and there is a right triangle determined. Finally, if , two measures of can be calculated: an acute and an obtuse angle . In this case, there may be one or two triangles determined. If , then the is not a solution.

In this problem, , which means that there are no solutions to that satisfy this triangle. If you got answers for this triangle, check that you set up your Law of Sines equation properly at the start of the problem.

Recall that there are 360 degrees in a circle which is equivalent to radians. In order to convert between radians and degrees use the relationship that,

.

Therefore, in order to convert from radians to degrees you need to multiply by . So in this particular case,

.

To convert radians to degrees, we need to multiply the given radians by .

It is important to recognize that the bleacher, the ground, and the support form a right triangle with the right angle formed by the intersection of the bleacher wall and the ground. We know the bottom of the support should only be 3ft from the bleacher wall on the ground and the bleacher wall is 10ft high. We will use the Pythagorean Theorem to solve for the length of the support, which is the hypotenuse of this right triangle. Our base of the triangle is 3 feet and the leg is 10 feet.

And so we need a support of 10.44 feet long.