380 likes | 451 Views
Discover the Pythagorean Theorem and learn how to apply it in solving right triangle problems. Explore the relationship between the sides of right triangles and the famous theorem by Pythagoras.
E N D
The Pythagorean Theorem c a b
We call it a right triangle because it contains a right angle.
in the The little square angle tells you it is a right angle. 90o
About 2,500 years ago, a Greek mathematician named Pythagorus discovered a special relationship between the sides of right triangles.
5 3 4 Pythagorus realized that if you have a right triangle,
5 3 4 and you square the lengths of the two sides that make up the right angle,
5 3 4 and add them together,
5 3 4 you get the same number you would get by squaring the other side.
Is that correct? ? ?
10 8 6 It is. And it is true for any right triangle.
The two sides which come together in a right angle are called
The two sides which come together in a right angle are called
The two sides which come together in a right angle are called legs.
The side across from the right angle is called the hypotenuse. a b
And the length of the hypotenuse is usually labeled c. c a b
The relationship Pythagorus discovered is now called The Pythagorean Theorem: c a b
The Pythagorean Theorem says, given the right triangle with legs a and b and hypotenuse c, c a b
then c a b
You can use The Pythagorean Theorem to solve many kinds of problems. Suppose you drive directly west for 48 miles, 48
Using The Pythagorean Theorem, 48 482 + 362 = c2 36 c
48 482 + 362 = c2 36 c Why? Can you see that we have a right triangle?
48 482 + 362 = c2 36 c Which side is the hypotenuse? Which sides are the legs?
So, since c2 is 3600, c is 60. And you end up 60 miles from where you started. So, since c2 is 3600, c is 48 36 60
15" 8" Find the length of a diagonal of the rectangle: ?
15" 8" Find the length of a diagonal of the rectangle: ? c b = 8 a = 15
c b = 8 a = 15
15" 8" Find the length of a diagonal of the rectangle: 17
Practice using The Pythagorean Theorem to solve these right triangles:
c 5 12 = 13
b 10 26
b 10 26 = 24 (a) (c)
12 b 15 = 9