The answer is 17/25. Hope this helps! :) I know how you feel!
Honestly? Just review your notes and try to work out the problems yourself before taking a look at the answer. You can also google specific topics that the test will cover and try the practice problems.
To solve this, notice that you have the angle component (I will call this a) and the x-component (the distance of you from the building) of a trig formula, and you are looking for the y-component. We will use the tangent formula, since this incorporates the angle, x, and y components.
1. Write the formula
tan(a) = y ÷ x
2. Rewrite to include the known values.
tan(79.9) = y ÷ 100
3. Solve for the unknown variable, y.
tan(79.9) × 100 = y ÷ 100 × 100
tan(79.9) × 100 = y
4. A fancy step that I call the "flip flop."
y = tan(79.9) × 100
5. Use a calculator to find the value (make sure the calculator is in "degree" and not "radians" mode).
y = 561.3968
6. Round the number as is appropriate for this problem.
Have a great day!
You multiply $120 by .55 to get the cost for tax which is $66 you add that to $120 to get $186