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!
