World 1-1 Pythagoras’ Theorem
When adding the areas of the two smaller squares,
their sum will ALWAYS equal the area of the larger
square for any right angled triangle.
c2
a2
b2
Using math we say c2=a2+b2
a
c
L
If we know any 2 side
lengths we can find the 3rd
using c2 = a2 + b2
b
The sides that make an L are called the legs, a or b.
The side across from the right angle is called the
hypotenuse, c.
Case I: The hypotenuse is unknown.
c =a +b
2
6m a
?m
c
b
8m
2
2
c = (6m) + (8m)
2
2
2
c = 36 m + 64 m
2
2
c = 100 m
2
2
c = ± 100 m
c = ±10 m
2
2
2
Case II:A leg is unknown.
b =c -a
2
30 m
20 m a
c
b
?m
2
2
b = (30m) - (20m)
2
2
2
= 900 m - 400 m
2
= 500 m
2
= ± 500 m
b » ±22.36 m
2
2
Homework
World 1-1