The proof of this fact is clear using trigonometry.

One can calculate the length of its sides using trigonometry.

The Scout must also measure the height of objects, such as trees, using simple trigonometry.

This time shift is represented as a phase angle and you use trigonometry in the calculations.

They got their rulers out and calculated the height using trigonometry.

Using simple trigonometry, this distance can be converted into an angle as seen from the bomber.

Then the distance to the star could be calculated using trigonometry.

If the grade is known, then the rate of ascent can be calculated using trigonometry.

As a mechanical engineer, I use trigonometry once in a while.

In any career in science, engineering, and mathematics you will use trigonometry.