# Homework Help: PF erased my problem anyways triangle problem

1. Oct 3, 2011

### flyingpig

1. The problem statement, all variables and given/known data

[PLAIN]http://img832.imageshack.us/img832/5249/unledhbk.png [Broken]

3. The attempt at a solution

Alright PF just erased all my work so here is my work without LaTex because I am too frustrated to do this all again

Basically I found the vectors

QP = <7,8,0>

|QP| = √113 ≈ 10.630

RP = <7,0,-5>

QR = <0,8,-5>

The others follow the same logic

I have dinner now so I will write out how I got the angles.

Last edited by a moderator: May 5, 2017
2. Oct 3, 2011

### flyingpig

I don't know why, but the angle at Q is right when I used those magnitudes...

3. Oct 4, 2011

### Staff: Mentor

I don't get this result for the angle at Q. Why do you think this is a right angle?

4. Oct 4, 2011

### flyingpig

Because it says it's right. No I am not talking "right angle - 90", I am was talking about "correct angle"

Damn you English language

5. Oct 4, 2011

6. Oct 4, 2011

### SammyS

Staff Emeritus
Why? What do you get for angle Q?

7. Oct 4, 2011

### flyingpig

50.434 degrees as I have.

My length for the vectors are wrong

8. Oct 4, 2011

### Staff: Mentor

They look fine to me. Those are the values (the lengths) that I got, and they asked you to round to 3 dec. places. Sometimes these computer-graded things are brain-dead.

9. Oct 4, 2011

### SammyS

Staff Emeritus
It asks for the exact values.

I.e. √(113)

10. Oct 4, 2011

### flyingpig

Yeah I asked my professor about that and she has yet to respond...

I really hate lazy professors giving people online assignments

11. Oct 4, 2011

### flyingpig

But it says to round to three decimal places

EDIT: OH CMON!!! WHAT?? THAT'S SO MISLEADING!!!

12. Oct 4, 2011

### SammyS

Staff Emeritus
The exact values for the lengths ... AND the angles rounded to 3 decimal paces.

13. Oct 4, 2011

### flyingpig

yeah I know, exact values =/= rounding.

I hate these stupid online problems, they just catch on picky reading mistakes

14. Oct 4, 2011

### flyingpig

Why am I complaining to you?...sorry lOL

15. Oct 4, 2011

### SammyS

Staff Emeritus
There really should have been better punctuation in the question.

16. Oct 4, 2011

### flyingpig

Different clauses, it should be

"Find the exact values of the length ,and angle rounded to three decimal places"

17. Oct 4, 2011

### Staff: Mentor

That caught me.