Right triangles

Right triangles show up everywhere: ladders against walls, ramps, shadows and most trigonometry on a test. This topic covers the two tools you need. First is the Pythagorean theorem, a squared plus b squared equals c squared, where c is always the hypotenuse, the side opposite the right angle. The classic slip is adding the squares when you are actually finding a shorter side, which needs subtraction. Second is choosing between sine, cosine and tangent. SOH CAH TOA only works once you have labelled the sides correctly from the angle you are using: opposite, adjacent and hypotenuse all change if you switch angles. Most wrong answers come from that labelling step, not from the calculator. Label first, then pick the ratio that uses the two sides you know. Always check that the hypotenuse comes out as the longest side. If it doesn't, something went wrong earlier. Work the pages in order and try each practice set before looking at the answers.