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View Full Version : Right angle triangle problems


raddog0426
Jul 7, 2008, 04:49 PM
for these questions on the right angle triangle I am given the length of one side and the degrees of one angle e.g.. Find the length of ac and angle b if ab=30 in length and angle a=60 degrees the 3 angles r 60 90 30 what formula do I use to now find the length of the other 2 sides



sin*hyp=opp
cos*hyp=adj
tan*adj=opp
or use other angle not to have opposite angle

Unknown008
Jul 7, 2008, 10:33 PM
A drawing will help you. There 's a little memo which I used in lower classes. Maybe it will b useful to you: SOH;CAH;TOA

Now, SOH is : sine (of angle)= opposite / hypotenuse
CAH: cosine (of angle)= Adjacent / hypotenuse
TOA: tangent (of angle)= Opposite / Adjacent

For Example (note that you didn't specify the positions of the letters on the triangle but the rule is the same):

http://tinypic.com/view.php?pic=rm4k10&s=3

Here, you can use : cos 60 = AB/AC and solve
Also, sin 30 = AB/AC to get the same answer

Once you get AC, can you get the last one. Note that you can use the tangent rule to find BC first.