- #1
songoku
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- 349
- Homework Statement
- Let A, B, C and D are 4 points in 3 dimensional space. If |AB| = 3, |BC| = 7, |CD| = 11 and |DA| = 9, calculate |AC| . |BD|
- Relevant Equations
- magnitude of vector
dot product
I don't really know where to start. Trying to use cosine rule but failed because no information about angle.
Thanks
Thanks