An escalator lifts people to the second floor of a building, 21 ft above the first floor. the escalator rises at a 30 degree angle. to the nearest foot, how far dies a person travel from the bottom to the top of the escalator?

We use the trigonometric function for this case. An escalator is an inclined path. We form a right triangle since we have given the value of the height. The height from the first floor to second floor is called the adjacent while the travelled distance of the people is called the hypothenuse. We use cosine function because we are given in terms of adjacent and hypothenuse. The ratio of cosine function is
cos x = a/h
where x is the angle
Solving for h,
h = a/(cos x) = 21/(cos 30) = 24.25 ft

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)