1. Pythagoras’ Theorem

2. Pythagoras’ Theorem states that for right angled triangles, the sum of the squares of the two shorter sides is equal to the square of the hypotenuse c2 a2 c a b2 b + =

3. c2 b2 a2 + = c2 a2 b2

4. Are these triangles right-angled triangles?
a2 + b2 = c2 15
= 152 12
= 225 9
So it’s a right angled triangle
a2 + b2 = c2 20
= 202 15
= 400 10
So it’s not a right angled triangle
Your turn!

5. Finding the length of the hypotenusex 7 12
c2 = a2 + b2
x2 =
x2 =
x2 = 193
x = √193
x = …
Your turn!
x = (3sf)

6. Finding the length of a shorter side11 4 x
c2 = a2 + b2
112 = x2
x2 =
x2 =
x2 = 105
x = √105
x = …
Your turn!
x = (3sf)