Geometry

1
Geometry

• Lesson 9-2

2
Converse of the Pythagorean Theorem

• Theorem 9-2 - If the square of one side of a
  triangle is equal to the sum of the squares of
  the other two sides, then the triangle is a right
  triangle.
• Ex. a 3, b 4, c 5
• 32 42 52
• 9 16 25 Right Triangle
• 3,4, and 5 are known as Pythagorean Triples

3
Theorem 9-3

• If the square of the longest side of a
  triangle is greater than the sum of the squares
  of the other two sides, then the triangle is an
  obtuse triangle.
• Ex. a 2, b 3, c 4
• 22 32 42
• 4 9 ?16
• 13 is less than 16 Obtuse Triangle

4
Theorem 9-4

• If the square of the longest side of a
  triangle is less than the sum of the squares of
  the other two sides, then the triangle is an
  acute triangle.
• Ex. a 4, b 5, c 6
• 42 52 62
• 16 25 ? 36
• 41 is greater than 36 Acute Triangle

5
Homework

• Pg. 470 - 471 1- 20 all (If not a right
  triangle state what type, acute or obtuse)