To determine your answer is a multi-step problem. First, since the gap between Casey's head and the top of the door opening is in cm, you need to convert the height of the door opening to cm by multiplying it by 100 (the number of cm in a m). So since the door opening is 2 m high, 2 m x 100 cm = 200 cm, so the door opening is 200 cm high. Subtracting the distance between the height of the door opening and the top of Casey's head (39 cm) from the top of the door opening (200 cm) will give you Casey's height: 200 cm - 39 cm = 161 cm. So Casey's height in cm is 161 cm. If you need to find it in meters, you would first have to divide 161 by 100 (100 cm in a m), so you'd have 1.61 m.
