Question

I'm looking at the top at 79.9 angle. I'm 100ft away. What's the height of the building?

Answer 1

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!

Answer 2

So this is a trig problem

so you have a right triangle
base=100 ft
from wher you are standing, it is a 79.9 angle to the top
we want to find the height of the tower or the opposite side
the base is  the adjacent side so you are looking for o/a or tan(79.9) since you know one of the sides so therefor
tan(79.9)=h/100
evaluate tan(79.9)
tan(79.9)=5.61396
5.61396=h/100
multiply both sides by 100
561.396=h
round to tenths place
561.4
the height=561.4 ft