VCAA 2008 Exam 1 8c)

[luffy]

Disclaimer: The below question(s) are extremely silly and show my incompetence. Please do not judge me haha.

In question 8c) of the 2008 VCAA exam 1, what answer were they actually looking for?

The question says "Prove ABCD is a rectangle" and the assessment report says "ABCD is a rectangle. * Answer given". What does that even mean?

I showed that the angles were at right angles and that opposite sides had the same vector. Is that correct?

[b^3]

Disclaimer: The below question(s) are extremely silly and show my incompetence. Please do not judge me haha.

In question 8c) of the 2008 VCAA exam 1, what answer were they actually looking for?

The question says "Prove ABCD is a rectangle" and the assessment report says "ABCD is a rectangle. * Answer given". What does that even mean?

I showed that the angles were at right angles and that opposite sides had the same vector. Is that correct?

Since ABCD is already a parallelogram, we know that the opposite sides are the same length. The only additional property that we have to show is that two adjacent sides are perpendicular, i.e. the dot product is zero. Since opposite sides are equal in length that means if one corner is 90, than the other three are two.

So in short, you only have to show that two adjacent sides are perpendicular with the dot product.

EDIT: really it should have had part bi and bii instead of b and c to show that the paralellogram info carried over, I didn't realise that untill I read the assesment report so I found out that I'd wasted time on proving things that were already given.

EDIT2: post number 1111 and it's 1:11pm!