Pythagoras' Theorem

Pythagoras was a Greek philosopher who discovered that in a right angled triangle (triangle with one angle 90 degrees) the hypotenuse squared , c2, was equal to the sum of the other sides squared, a and b. The hypotenuse is the longest edge and is opposite the right angle, a and b are the adjacent sides, next too, the right angle. 

We call this Pythagoras' Theorem: a2+b2=c2

If we know two of the three sides we can use this theorem to work out the other, by subbing in the values known and rearranging.

KC

Related Maths GCSE answers

All answers ▸

Q: How to solve the simultaneous equations 3x+2y=7 and 5x+y=14


Prove that 0.5757... (recurring) = 19/33. Hence, write 0.3575757... (recurring) as a fraction in its lowest terms.


The point P has coordinates (3, 4) The point Q has coordinates (a, b) A line perpendicular to PQ is given by the equation 3x + 2y = 7 Find an expression for b in terms of a.


A rectangle has an area of 20 cm2. Its length and width are enlarged by scale factor 3. Find the area of the enlarged rectangle.