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Pythagoras. Pythagoras. A square is a shape with four equal sides Example: All its angles are ninety degrees. Pythagoras. Another meaning of square is to square a number The square of a number is the number times itself 1 squared = 1 2 squared = 4 3 squared = 9 4 squared = 16
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Pythagoras • A square is a shape with four equal sides • Example: • All its angles are ninety degrees
Pythagoras • Another meaning of square is to square a number • The square of a number is the number times itself • 1 squared = 1 • 2 squared = 4 • 3 squared = 9 • 4 squared = 16 • 5 squared = 25
pythagoras • The area of a square with side 4 cm is 16 square cm
pythagoras • The area of a square with side 3 cm is 9 square cm
pythagoras • The area of a square with side 5 cm is 25 square cm
pythagoras Blue area = c x c = c squared
pythagoras Blue area = a squared plus b squared But this must equal c squared because all shapes are still the same Tis works for every right angled triangle
PYTHAGORAS • Pythagorean triads http://youtu.be/FhPWIQSIQqw(start at 3 min 45 secs) • Proof of Pythagoras’ theorem (start at 1 min 52 secs) http://youtu.be/y9MqD7LN0xY • History http://youtu.be/b8DrYz_cKR0
pythagoras Challenge: Find another Pythagorean triad with all three numbers under 20