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

Function name Abbreviation The three ratios of a right triangle are called trigonometric functions of acute angles and are defined as follows: Function name Abbreviation

Moving Forward If you don’t get my answers it’s because your calculator is not in degrees . . . . . . Put it in degrees. If you’re not sure how to do this, google it!

Try these sin (18°) cos (22.7°) tan (11.9 °) sin (84.3°) 0.309 0.923 sin (18°) cos (22.7°) tan (11.9 °) sin (84.3°) cos (8.7°) tan (49°) tan-1 (1.7) sin-1 (0.50) cos-1 (0.37) cos-1 (0.84) tan-1 (2.4) sin-1 (0.38) 0.211 0.995 0.988 1.15 59.5° 30.0° 68.3° 32.9° 67.4° 22.3° On most calculators, the inv is shift or 2nd of the sine, cos or tan If you’re looking for sin-1 cos-1 tan-1

hypotenuse opposite adjacent The hypotenuse (hyp) is ALWAYS the side opposite the right angle The opposite side (opp) is ALWAYS the side opposite angle under consideration The adjacent side (adj) is ALWAYS the remaining side

c = Hypotenuse = 13 b = Opposite = 12 13 12 Find the value of each of the three trigonometric functions of the angle c = Hypotenuse = 13 b = Opposite = 12 13 12 Adjacent

To determine an angle from its sin or cos or tan, use the inv function You’re looking for sin-1 cos-1 tan-1 On most calculators, the inv is shift or 2nd of the sine, cos or tan 0.923 Type in 2.4 sin-1 (0.923) tan-1 (2.4) cos-1 (0.385) 0.385 67.4°

c a b To solve a right triangle means to find the missing lengths of its sides and the measurements of its angles.

hyp c 4 opp b adj

h 25 h = 23.49