## chris_parks In a 30-60-90 triangle, the hypotenuse is 20 feet long. Find the length of the length of the long leg and the short leg 2 years ago 2 years ago

1. josephniel14

short - 10 long - $10\sqrt{3}$

2. satellite73

short leg is half of the hypotenuse

3. josephniel14

:))

4. Sriram

20cos60=10 and 20sin60=10 *(30)^1/2

5. josephniel14

@siriam: LOLwut?

6. josephniel14

You can just use some formulas because the given is a special triangle.

7. satellite73

you need to trig for this. short side is half of long side because it is half of an equilateral triangle then the other side comes from pythagoras.

8. satellite73

i meant you need NO trig

9. Sriram

dude 20/short side=cos60 & 20 / long side=sin60 whats wrong in it??

10. Khu052

there's nothing wrong with it, it's just the harder option.

11. josephniel14

Nothing. You can just use simple equations for special triangles.

12. satellite73

nothing wrong except that the only reason you know the cosine of 60 degrees is because you know the ratios, not the other way around!

13. ARASH_D

short=20*sin30=10 long=20*sin60=10$\sqrt{3}$

14. josephniel14

Why are you applying trigonometry on such easy questions?

15. josephniel14

You can just use simple equations on special triangles.

16. josephniel14

in a 30-60-90, a = short side, b = long side, c = hypotenuse c = 2a ; b = $a \sqrt{3}$

17. ARASH_D

i think u did it too.i have no problem with trigonometry

18. robtobey

$\text{long} \text{side}=20\text{Cos}\left[\text{ArcSin}\left[\frac{10}{20}\right]\right]=10 \sqrt{3}$$20^2=10^2+\left(10 \sqrt{3}\right)^2, 400=100+300, 400= 400$