## Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.

## Question

junior college 1 | H2 Maths
One Answer Below

Anyone can contribute an answer, even non-tutors.

##### Sai

chevron_right chevron_right

It's vector question

Date Posted: 7 months ago
Views: 44

### See 1 Answer

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
##### Eric Nicholas K's answer
3767 answers (Tutor Details)
1st
We only need two conditions to prove that ABCD is a parallelogram.

One, the direction of the vector AB (line AB) is the same as that of the vector DC (line DC). When two direction vectors are the same, the two lines are parallel.

Two, the distance AB must also be the same as the distance DC.

Once this is achieved, you will realise that no matter what, the other two lines AD and BC will also be parallel and equal in length. Hence, we only need the two conditions above to prove that ABCD is a parallelogram.

If the diagonals are equal in length, then the shape is definitely a rectangle. We cannot prove, however, that ABCD is a square; we will need another condition that AB = AD.
Date Posted: 7 months ago