Quick Trigonometry Facts :
06-30-2007
Some helpful definitions and concepts of Trigonometry: Trigonometry: Comes from 2 Greek terms- trigon (meaning triangle) and metron (meaning measure.) The study of Trigonometry involves triangle measurements. Trigonometric Ratio: A ratio of the lengths of sides of a right triangle. The three most common trigonometric ratios are sine, cosine, and tangent. (Others include cotangent, secant and cosecant.)
Sine (Sin) = Leg Opposite of angle .................Hypotenuse of triangle
Cosine (Cos) = Leg Adjacent of angle ....................Hypotenuse of triangle
Tangent (Tan) = Leg Opposite of angle .......................Leg Adjacent of angle
A way to remember these ratios is the saying: SOH - CAH - TOA For those triangles that are not triangles, two following equations can be used to solve missing measures in any triangle. First, The Law of Sines.
The equation is as: Sin A = Sin B = Sin C a.......... b......... c
Where in triangle ABC, A, B, and C represent the angles of the triangle, and a, b, and c are the measures of the sides OPPOSITE the angles, respectively. Which brings us to the Law of Cosines, as follows:
a^2 = b^2 + c^2 -2bc Cos A
b^2 = a^2 + c^2 -2ac Cos B
c^2 = a^2 + b^2 -2ab Cos C
(example: a^2 is read "A Squared.")
In any triangle ABC, a,b, and c represents the measures of sides opposite angles A, B, and C, respectfully. The Law of Cosines can be used to find missing measures in a triangle if you know the measures of 2 sides and the included angle.
Good luck and I hope this helps!
__________________ Just ask if you need any help!
Last edited by kiddietyte; 06-30-2007 at 10:11 PM.
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