You are Here: Home

Triangle

Announcements Posted on
Take our survey to be in with the chance of winning a £50 Amazon voucher or one of 5 x £10 Amazon vouchers 28-05-2016
1. Given the three points A (3,4,0) , B (8,0,6) , C (0,5,12) in space . find
1)Area of the triangle ABC
2)the length of the three medians of this triangle
3)The measure of the angle ABC
4)Equation of the plane ABC
2. what have you done so far?
3. At least try it before coming on tsr with your homework questions... Why should we do it for you?
4. "Sigh" this is not a homework
5. I found 4) and 1) i need just a little hint for 2) and 3)
6. again, what have you done so far?

i have no idea what 2) is asking.
hint for q3 = cosine rule
7. For 1)
8. (Original post by MAA_96)
2)the length of the three medians of this triangle
Start by finding the coordinates of the centroid...

You should know what to do next.

If not:

Spoiler:
Show

Call the centroid .

Median from

Median from

Median from
9. (Original post by z0tx)
Start by finding the coordinates of the centroid...
Do i have to use midpoint and use the distance formula or...to find that ?
10. (Original post by MAA_96)
Do i have to use midpoint and use the distance formula or...to find that ?
Nope, midpoints would be a waste of time.

The coordinates of the centroid are:

Keep that in mind for future problems involving triangles!

Also, in case you don't know: the median is 3/2 of the distance between the vertex in question and the centroid.
11. I should that yes, you could find the three midpoints and calculate the three distances, but why do something thrice when you can do it once?
12. Nice,but why did you choose centroid here?
13. (Original post by MAA_96)
Nice,but why did you choose centroid here?
I just told you. Finding the centroid (i.e. a single point) is quicker than finding all the midpoints (i.e. three points).
14. Alright,thank you.

Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: June 9, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

Don't be a half-term hermit

How to revise this week and still have a life

Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read here first

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams