What are the rules of trichotomy???

To make a monster appear large in a movie, a human actor wore a costume and walked through a scale model of a city. the scale used was 1 inch = 15 feet. the actor is 60 inches tall. how tall does the monster appear in the movie? question 5 options: 720 feet 75 feet 4 feet 900 feet

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Can you me find the missing length. i attached an image.