View Full Version : Need some math help.
I need some trigonometry help to be exact. I�m and no good at math at all. So this is killing me.
I�m given a problem to solve�
�A right isosceles triangle has a hypotenuse of 8 inches. What is the length of each leg? Round your answer to the nearest tenth of an inch.�
And it shows the right triangle with only the hypotenuse (8 inches.)
A page or two back from where the problem is, the text book I�m looking at is �teaching� me about a 45�-45�-90� right triangle. It says it has side lengths in the ratio 1:1: ***8730;2.
I�m I right in thinking that somehow I�m supposed to use that ratio to solve the problem? I don�t understand how though. :confused:
LimpBIT
2006-09-20, 05:45 PM
sin=opposite/hypotenuse. Do the sin90=X/10 x being one of the legs. so therefor 10sin90 should give you X
Rayder
2006-09-20, 06:01 PM
First off, the sin90 = 1. So 10 x 1 = 10 which is not the right answer (besides, the hypotenuse is 8).
Simply divide the hypotenuse (8) by ***8730;2.
Since the ratio of the sides of an isosceles right triangle is 1:1:***8730;2, to find the hypotenuse one would multiply ***8730;2 by the value of one of the legs (which are equal so it doesn't matter which).
Thus do we see that to get the value of the legs when we have the hypotenuse all we need do is divide the value of the hypotenuse by its ratio (***8730;2).
LimpBIT
2006-09-20, 07:35 PM
ahh yea Rayder your right. I kinda forgot all my math, just trying to give some of what I remembered :\
First off, the sin90 = 1. So 10 x 1 = 10 which is not the right answer (besides, the hypotenuse is 8).
Simply divide the hypotenuse (8) by ***8730;2.
Since the ratio of the sides of an isosceles right triangle is 1:1:***8730;2, to find the hypotenuse one would multiply ***8730;2 by the value of one of the legs (which are equal so it doesn't matter which).
Thus do we see that to get the value of the legs when we have the hypotenuse all we need do is divide the value of the hypotenuse by its ratio (***8730;2).
Thanks guys!
So to get lengths of the legs, divide the hypotenuse (8) by ***8730;2.
8/***8730;(2) = 5.656854.... round to the nearest tenth and my answer is 5.7 inches for both legs right?
Strygun
2006-09-20, 08:33 PM
Thanks guys!
So to get lengths of the legs, divide the hypotenuse (8) by ***8730;2.
8/***8730;(2) = 5.656854.... round to the nearest tenth and my answer is 5.7 inches for both legs right?
only for that type of isos. triangle.
Yeah just the 45***176;-45***176;-90***176; right triangles isosceles right?
Strygun
2006-09-20, 11:10 PM
Yeah just the 45***176;-45***176;-90***176; right triangles isosceles right?
yes
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