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smurfy14
 5 years ago
Word problem help! (File attached)
smurfy14
 5 years ago
Word problem help! (File attached)

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0do you know the law of cosines?

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0we learned it like 2 yrs ago but i forgot

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok I'll tell you: c^2=a^2+b^22*a*b*cos(C) for a triangle ABC, c is the side across from C, a across from A, b across from B. C inside of cosine is the angle C.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0you have a triangle if sides 20, 15, 7. use the law of cosines to find the angle where sides of length 7 and 15 meet. Then you subtract that from 180 to find complimentary angle. Now you have an angle and hypotenuse of a right triangle so you can find the height of the ladders.

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0ok so what is the angle measure?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0you have to find it with law of cosines, I got about 126.9 degrees

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0law of cosines? how do you find that? with ur calc?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[c^2=a^2+b^22abcos(\theta)\] c=20 a=7 b=15 solve for theta. You can use a calculator

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0dont have a calc on me but ok what do you do after you get 126.9?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0you can find its compliment by taking 180126.9=53.1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Now you have a right triangle of hypotenuse 15 and angle 53.1 right?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0and the leg opposite the angle is your height

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so 15*sin(53.1)=h h=12

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0but i am probably wrong again

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0it cant be that big the hypotenuse is 15

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0oh where do i put the angle 53.1? like if i were drawing a pic of it

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0does 53.1 go on the green or red dot?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0neither those arent the angles I was talking about. slide both of those dots down along the side of length 15. the red one would then be 53.1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0we used law of cosines to find the angle opposite side of length 20

smurfy14
 5 years ago
Best ResponseYou've already chosen the best response.0so the one diagnol to the the height of the building? ok

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yep the one opposite the height of the building is 53.1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh there's a much easier way to do this too. do you want to know the simpler way?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0well i'll just post it here and hopefully you see it. call the distance from the bottom of the 15 length ladder to the base of the wall x, and the height h. There are two right triangles now. One of sides 20,7+x,h and one of sides 15,x,h. By pythagorean theorem: 20^2=h^2+(x+7)^2 15^2=h^2+x^2 solve for h^2 in both equations and set them equal. h^2=20^2(x+7)^2=15^2x^2 400x^214x49=225x^2 126=14x x=9 so pluging back in to the 15 hypotenuse triangle equation we get h=12
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