Warm Up: Find the missing angle measurements Right Angle 18 ° Missing Angle Right Angle 54 ° Missing Angle The angles of ALL triangles  add up to 180 degrees
Special Right Triangles Chapter 11 Section 5
Multiplying Square Roots For nonnegative numbers, the square root of a product equals the product of the square roots. This is how you determine answers not on page 746. √ 18 = √ 9  ∙ 2  = √9 ∙ √2 = 3 ∙ √2
45 ° -45 ° -90 °  Triangles Isosceles Right Triangles also known as:  45 ° -45 ° -90 °  triangles. Use the degrees to identify these types of triangles.
How 45-45-90 Triangles Work C ² = A² + B² ← Pythagorean Theorem *Isosceles triangles have two equal length legs.*   Therefore, A and B are the same length! C² = 2x²  ← the length of the leg is now represented by x. C = √2x² ← Undo the square on the c. C = √2 ∙ √x² ← Multiplying Square Roots. C = √2 ∙ x ← The hypotenuse of a 45-45-90 triangle is always  √ 2 multiplied by the length of the leg.
45-45-90 Triangles Isosceles Right Triangle 90 ° 45 ° 45 ° X X Hypotenuse = leg  x √2 45-45-90 triangles have congruent leg lengths and the hypotenuse is the length of the leg multiplied by  √2.
What is the Square Root of 2? √ 2 =  1.41423562 So round answers to the nearest tenth unless asked to do otherwise.
30 ° -60 ° -90 °  Triangles Two 30 ° -60 ° -90 °  triangles are formed when you cut an Equilateral Triangle in half. The Hypotenuse of each 30-60-90 is twice the length of the shorter leg. Use Pythagorean Theorem to find the length of the longer leg.
30 ° -60 ° -90 °: Determine Long Leg C ² = A² + B² (2x)² = x² + B² ← B is the length of the long leg. 4x² = x² + B² 3x² = B² ← Minus x ² √ 3x² = B ← Undo square root √ 3 ∙ x = B ← Multiply square root The length of the longer leg = the  √3 ∙ the length of the shorter leg.
Assignment #35: Handout
Cool Website On Triangles http://www.800score.com/content/guide7b2.html

11.5 Special Right Triangls

  • 1.
    Warm Up: Findthe missing angle measurements Right Angle 18 ° Missing Angle Right Angle 54 ° Missing Angle The angles of ALL triangles add up to 180 degrees
  • 2.
    Special Right TrianglesChapter 11 Section 5
  • 3.
    Multiplying Square RootsFor nonnegative numbers, the square root of a product equals the product of the square roots. This is how you determine answers not on page 746. √ 18 = √ 9 ∙ 2 = √9 ∙ √2 = 3 ∙ √2
  • 4.
    45 ° -45° -90 ° Triangles Isosceles Right Triangles also known as: 45 ° -45 ° -90 ° triangles. Use the degrees to identify these types of triangles.
  • 5.
    How 45-45-90 TrianglesWork C ² = A² + B² ← Pythagorean Theorem *Isosceles triangles have two equal length legs.* Therefore, A and B are the same length! C² = 2x² ← the length of the leg is now represented by x. C = √2x² ← Undo the square on the c. C = √2 ∙ √x² ← Multiplying Square Roots. C = √2 ∙ x ← The hypotenuse of a 45-45-90 triangle is always √ 2 multiplied by the length of the leg.
  • 6.
    45-45-90 Triangles IsoscelesRight Triangle 90 ° 45 ° 45 ° X X Hypotenuse = leg x √2 45-45-90 triangles have congruent leg lengths and the hypotenuse is the length of the leg multiplied by √2.
  • 7.
    What is theSquare Root of 2? √ 2 = 1.41423562 So round answers to the nearest tenth unless asked to do otherwise.
  • 8.
    30 ° -60° -90 ° Triangles Two 30 ° -60 ° -90 ° triangles are formed when you cut an Equilateral Triangle in half. The Hypotenuse of each 30-60-90 is twice the length of the shorter leg. Use Pythagorean Theorem to find the length of the longer leg.
  • 9.
    30 ° -60° -90 °: Determine Long Leg C ² = A² + B² (2x)² = x² + B² ← B is the length of the long leg. 4x² = x² + B² 3x² = B² ← Minus x ² √ 3x² = B ← Undo square root √ 3 ∙ x = B ← Multiply square root The length of the longer leg = the √3 ∙ the length of the shorter leg.
  • 10.
  • 11.
    Cool Website OnTriangles http://www.800score.com/content/guide7b2.html