Learn about the Pythagorean theorem. The Pythagoras theorem is a fundamental relation among the three sides of a right triangle. It is used to determine the missing length of a right triangle. The ...

Use Pythagoras’ theorem to show a triangle is right-angled or to find one side of a right-angled triangle when two sides are known. Make sure you are confident at substituting into and manipulating ...

a missing side in a right-angled triangle when another side and an angle are known. a missing angle in a right-angled triangle when two sides are known. In these formulae, the Greek letter θ (theta) ...