1. Pythagorean Theorem - Thurs, Oct 7
Unit C.1
Pythagorean Theorem
SEI.3.AC.4Use, with and without appropriate technology, coordinate geometry to represent and solve problems including midpoint, length of a line segment and Pythagorean Theorem.

2. Review: Right Triangle
Pythagorean Theorem - Thurs, Oct 7
Unit C.1
Review: Right Triangle
What is a right triangle?
A triangle with a right angle
What are a and b called?
the legs
What is c called?
the hypotenuse c
Go over this with the students. Remind them of what constitutes a right triangle. a b
FHS
Chapter 5

3. The Pythagorean Theorem
Pythagorean Theorem - Thurs, Oct 7
Unit C.1
The Pythagorean Theorem
The Pythagorean Theorem states that in a right triangle, the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse.
a2 + b2 = c2 c
This is the main concept. Point out what a simple equation that it is. Be sure to emphasize that this only works with right triangles. a b
FHS
Chapter 5

4. Pythagorean Theorem - Thurs, Oct 7
Unit C.1
The Pythagorean Theorem can be used to find missing parts of a right triangle.
If the one leg is 3 inches and the hypotenuse is 5 in., we can find the other leg.
a2 + b2 = c2
b2 = 52
9 + b2 = 25
b2 = 16
b = 4 in.
5 in. b
When this presentation is complete, give an assignment containing problems in which the students have to find the hypotenuse of each triangle, given the two legs. Another lesson can be taught [or this presentation can be extended at a later time] to show how to find one leg, given the hypotenuse and the other leg.
3 in.
FHS
Chapter 5

5. Find the hypotenuse if given the two legs of 5 ft and 12 ft.
Pythagorean Theorem - Thurs, Oct 7
Unit C.1
Find the hypotenuse if given the two legs of 5 ft and 12 ft.
a2 + b2 = c2 → = c2
= c → c2 = 169
c = 13 in.
Can these numbers be the sides of a right triangle? 4, 5 and 6
Square all three numbers. Add the two smallest ones together. Is this the same as the largest square?
a2 = b2 = c2 = 36
Is = 36?
When this presentation is complete, give an assignment containing problems in which the students have to find the hypotenuse of each triangle, given the two legs. Another lesson can be taught [or this presentation can be extended at a later time] to show how to find one leg, given the hypotenuse and the other leg.
FHS
Chapter 5