Question

One end of the diameter of a circle lies on (-7, 16) and the other on the x-axis, and the centre lies on the y-axis. The coordinates of the centre and the other end of the diameter, respectively, are:

[1 mark]

• A. Centre (8, 0), other end (0, 7)
• B. Centre (0, 8), other end (7, 0)
• C. Centre (0, 4), other end (4, 0)
• D. Centre (4, 0), other end (0, 4)

Answer 1

The correct option is B Centre (0, 8), other end (7, 0)

We know that the centre of a circle is the midpoint of the diameter.


$\therefore (\frac{(-7+x)}{2},\frac{(16+0)}{2})=(0,y)$

$\Rightarrow -7+x=0\Rightarrow x=7\Rightarrow 16+0=2y\Rightarrow y=8$

$\therefore \text{The centre is (0, 8) and the other end of the diameter is (7, 0).}$