A set of stairs is being built as shown. What is the height of the stair?
3 triangles form stairs. Each triangle has a side length of 9 inches and hypotenuse of 15 inches.
The stair is___inches high.

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.