How tall’s the school?

We are using mirrors to determine the height of the school.  Using the law of reflection we can create 2 similar triangles.  One between the heigt of the school, and the length of the ground between the school and the mirror.

And one involving the height to the observer’s eyes, and the distance from the observer’s feet to the mirror.  

We can determine the proportionality constant and calculate the height of the school!