A staircase has an angle of elevation of 28° anı covers a total distance of 17 feet. What is the
horizontal length covered by the staircase?

Hi there!

We can use right-triangle trigonometry to solve.

We are given the HYPOTENUSE and ADJACENT sides, so we must use cosine in this instance.

cosθ = Adjacent/Hypotenuse

We can plug in what is given:

cos(28) = A/17

Solve for 'A':

17cos(28) = 15.01 ft

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

the answer is c)8

step-by-step explanaction: