Finding the Adjacent and Opposite Sides in a Right TriangleDate: 06/12/2008 at 20:49:13 From: D Subject: trying to tell the difference between adjacent and opposite What is the difference between adjacent and opposite and how do I find it? I can't tell the difference but I think adjacent is across the hypotenuse Date: 06/12/2008 at 23:03:20 From: Doctor Peterson Subject: Re: trying to tell the difference between adjacent and opposite Hi, D. In everyday usage, "adjacent" means "next to", and "opposite" means "across from". That is true in math as well. In trigonometry, if you imagine yourself standing on one acute angle of a right triangle, the two sides that meet at your corner are the hypotenuse (the longest side, across from the right angle) and one of the two legs. Since that one is NEXT TO you, it is the ADJACENT leg. There is a third side, which is ACROSS FROM you. That is the OPPOSITE leg. Note that it matters which angle you are calling "yours"; you can only say that a leg is adjacent or opposite in relation to a specific vertex (angle). The leg adjacent to that angle is the one that forms part of the angle; the leg opposite to the angle is the one that doesn't touch that vertex. In the following pictures, I have labeled different vertices as A. In each case, the leg labeled "adj" is next to A, and the leg labeled "opp" is across from A: + A hyp / | hyp / | / |opp / |adj / | / | A-----------+ +-----------+ adj opp If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/ |
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