We can measure the height of our rocket if we assume the rocket ascends vertically. We can use a mathematical process called trigonometry. Trigonometry has three very special formulae called Sin, Cos and Tan. We will use the Tan formula to help us find the height of our rocket. With this formula we only need to know the distance we are from the launch site and the angle we have to raise our eyes to see the rocket at its heighest point.

Firstly construct an inclinometer.