Trigonometry is used for calculations involving angles and triangles.
You may have heard of the 'Pythagorean Theorem' and 'sine, cosine & tan'?
Trigonometry is used in many industries, including construction.
Work through the modules under the drop down arrow above to improve your understanding of trigonometry.
N.B. Scientific calculators include 'sin,' 'cos' & 'tan' buttons which are required for some calculations involving trigonometry.
Click the link & scroll to find tutorials on your calculator's particular brand...
https://www.youtube.com/c/HDCalcs/video
For example, watch the video below from HD Calcs on how to use trigonometric functions.