3.8: Square with diagonal AC and column vectors

0606/22/M/J/21 — Question 6 · 8 marks

The points A(5,4)A(5, -4) and C(11,6)C(11, 6) are such that ACAC is the diagonal of a square ABCDABCD.
(a)
Find the length of the line ACAC.
[2]
(b)(i)
The coordinates of the centre EE of the square are (8,y)(8, y). Find the value of yy.
[1]
(b)(ii)
Find the equation of the diagonal BDBD.
[3]
(b)(iii)
Given that the xx-coordinate of BB is less than that of DD, write EB\overrightarrow{EB} and ED\overrightarrow{ED} as column vectors.
[2]