Erm...Originally posted by lavastar:1a ) The triangle ABC has its verticles at the points A (0,0,1) , B(1,0,1) , C(2,1,3). Find the area of the triangle
b) THe parallelogram ABCD has three of its verticles at the points (1,2,-1), (1,3,2) and (-1,3,-1) . Find the area of the parallelogram. ( Ans : 7 )
For this question, how can i know which verticles correspond to which side of the figure? no diagrams are given..
2. Given the points A ( 1,2,-1), B(3,4,0) , C(1,5,-2) and that O is the origin, find the shortest distance of B on the line AC. ( ans : 0.5 X sq root 26)
For this question , im unsure of what the question wans me to find.
Thanks for any help
1a)Originally posted by lavastar:1a ) The triangle ABC has its verticles at the points A (0,0,1) , B(1,0,1) , C(2,1,3). Find the area of the triangle
By inspection, we can see that (1,2,-1) is beside (1,3,2) and (1,2,-1) is also beside (-1,3,-1). So is area of triangle = 1/2 of parallelogramOriginally posted by lavastar:b) THe parallelogram ABCD has three of its verticles at the points (1,2,-1), (1,3,2) and (-1,3,-1) . Find the area of the parallelogram. ( Ans : 7 )
Try and visualiseOriginally posted by lavastar:For this question, how can i know which verticles correspond to which side of the figure? no diagrams are given..
Treat AC as a lineOriginally posted by lavastar:2. Given the points A ( 1,2,-1), B(3,4,0) , C(1,5,-2) and that O is the origin, find the shortest distance of B on the line AC. ( ans : 0.5 X sq root 26)
For this question , im unsure of what the question wans me to find.
it shld be sin angle BAM, so i think tt's where ur answer went off =)Originally posted by eagle:Length BM = length BA * cos angle BAM
= 5 / sqrt (10)(
yup, you are right.Originally posted by SBS261P:it shld be sin angle BAM, so i think tt's where ur answer went off =)
can derive formula oneOriginally posted by SBS3625D:Haiya, draw the diagram and you can see better.
Use the formula 0.5 x sin........ to find the area.
What fuck. Forgot the formula already. Siao liao!
I got it.Originally posted by eagle:can derive formula one
Last time all my vectors tutorial, I derive all these stupid formulas... Just get the basic formulae right can liao.
But then, I got quite a number of things to do, so do mentally then save time...