Trigonometric Ratios  in Right Triangles
Trigonometric Ratios  are based on the Concept of  Similar Triangles!
All 45º- 45º- 90º Triangles are Similar! 45 º 2  2  45 º 1  1  45 º 1
All 30º- 60º- 90º   Triangles are Similar! 1 ½ 2 4 60º  30º 60º  30º 2 60º  30º 1
All 30º- 60º- 90º   Triangles are Similar! 10 60º  30º 5 2 60º  30º 1 1 60º  30º
A triangle in which one angle is a right angle is called a  right triangle .  The side opposite the right angle is called the  hypotenuse , and the remaining two sides are called the  legs  of the triangle. c b a
Naming Sides of Right Triangles  Hypotenuse  Side Adjacent  Side Opposite  
The Tangent Ratio There are a total of six ratios that can be made with the three sides.  Each has a specific name.  Side Adjacent   Hypotenuse Side Opposite   Tangent   
The Six Trigonometric Ratios (The SOHCAHTOA model) S  O  H  C  A  H  T  O  A  Side Adjacent   Hypotenuse Side Opposite  
The Six Trigonometric Ratios The Cosecant, Secant, and Cotangent of     are the Reciprocals of  the Sine, Cosine,and Tangent of    Side Adjacent   Hypotenuse Side Opposite  
Reciprocal Identities Quotient Identities
 
Find the value of each of the six trigonometric functions of the angle  Adjacent 12 13 c  = Hypotenuse = 13 b   = Opposite = 12
 
25 h h  = 23.49
Solving a Problem with the Tangent Ratio 60º  53 ft h = ? We know the angle and the  side adjacent to 60º.  We want to  know the opposite side.  Use the tangent ratio: Why? 1 2

Right triangle trigonometry

  • 1.
    Trigonometric Ratios in Right Triangles
  • 2.
    Trigonometric Ratios are based on the Concept of Similar Triangles!
  • 3.
    All 45º- 45º-90º Triangles are Similar! 45 º 2 2 45 º 1 1 45 º 1
  • 4.
    All 30º- 60º-90º Triangles are Similar! 1 ½ 2 4 60º 30º 60º 30º 2 60º 30º 1
  • 5.
    All 30º- 60º-90º Triangles are Similar! 10 60º 30º 5 2 60º 30º 1 1 60º 30º
  • 6.
    A triangle inwhich one angle is a right angle is called a right triangle . The side opposite the right angle is called the hypotenuse , and the remaining two sides are called the legs of the triangle. c b a
  • 7.
    Naming Sides ofRight Triangles  Hypotenuse  Side Adjacent Side Opposite 
  • 8.
    The Tangent RatioThere are a total of six ratios that can be made with the three sides. Each has a specific name.  Side Adjacent  Hypotenuse Side Opposite  Tangent  
  • 9.
    The Six TrigonometricRatios (The SOHCAHTOA model) S O H C A H T O A  Side Adjacent  Hypotenuse Side Opposite 
  • 10.
    The Six TrigonometricRatios The Cosecant, Secant, and Cotangent of  are the Reciprocals of the Sine, Cosine,and Tangent of   Side Adjacent  Hypotenuse Side Opposite 
  • 11.
  • 12.
  • 13.
    Find the valueof each of the six trigonometric functions of the angle Adjacent 12 13 c = Hypotenuse = 13 b = Opposite = 12
  • 14.
  • 15.
    25 h h = 23.49
  • 16.
    Solving a Problemwith the Tangent Ratio 60º 53 ft h = ? We know the angle and the side adjacent to 60º. We want to know the opposite side. Use the tangent ratio: Why? 1 2