IF YOU KNOW TWO SIDESAnd you want to know an angle.* If you know the legs only use the inverse tangent.Examples:tan-1(Lleg ÷ Sleg) = Langletan-1(Sleg ÷ Lleg) = Sangle* If you know a leg and the hypotenuse use either inverse sine (sin-1) or inverse cosine (cos-1) depending on what angle you want.Examples:sin-1(Sleg ÷ Hyp) = Sanglesin-1(Lleg ÷ Hyp) = Langlecos-1(Sleg ÷ Hyp) = Langlecos-1(Lleg ÷ Hyp) = SangleNever divide the Hypotenuse by a leg. (Hyp leg)! It gives a wrong ratio for our use.IF YOU KNOW AN ANGLE AND A SIDEAnd you want to know another side.* If you know a leg and an angle and want to know the other leg always use tangent.Examples:tan(Sangle) x Lleg = Slegtan(Langle) x Sleg = LlegNote the ratios: tan(Sangle) is always less than one, So when you multiply it times the larger leg it will give you something shorter. tan(Langle) is always greater than one. When you multiply it times the smaller leg you will get something longer.* If you know a leg and an angle and want to know the hypotenuse divide the legs by sine or cosine of an angle.Examples:Sleg ÷ sin(Sangle) = HypSleg ÷ cos(Langle) = HypLleg ÷ sin(Langle) = HypLleg ÷ cos(Sangle) = Hyp* If you know the hypotenuse and an angle use either Sine or Cosine.Examples:sin(Sangle) x Hyp = Slegsin(Langle) x Hyp = Llegcos(Sangle) x Hyp = Llegcos(Langle) x Hyp = SlegNotice how the sine or cosine of an angle is always less than one. Remember ratio. The legs are always smaller than the hypotenuse. This number must be less than one so that when you multiply it times the hypotenuse you will always get something shorter than the hypotenuse.
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