The Important of Horizontal line in measuring angle of Elevation and Depression

Remember, we need to measure from the horizontal in order to get the angle of Elevation and Depression. Common mistake is often occur when measuring the angle of Elevation and Depression NOT from the horizontal.






Distance and height; these two play an important role in order to measure whether the angle of Elevation or Depression. In some cases, the situation will give us the information on height and the value of angle, then we need to find the distance and vice versa.

Let us look at the situation below and try to solve by using your own knowledge.

Suppose that we want to find the height of this tree.

We mark point A and what is the distance from the base of the tree.

Then we measure the angle of elevation from A to the top of the tree.

Now,

We have measured and so we can calculate tan() and thus we can find h, which is the height of the tree.