Question

Find the radius of a circle, given that the centre is at (2, –3) and the point
(–1, –2) lies on the circle.

Answer 1

Answer:

Given that centre of the circle is O(2,-3) and point A(-1,-2) lies on the circle i.e.

Distance between points A and O will be the radius of the circle as A lies on the circumference of the circle .

Distance between centre and the point lies on the circle will be equal to radius of the circle.

So using distance formula:-

$Distance \: AO = \sqrt{ {(2 + 1)}^{2} + {( - 3 + 2)}^{2} } \\ = \sqrt{ {3}^{2} + {1}^{2} } \\ = \sqrt{9 + 1} \\ = \sqrt{10}units$

so radius of circle will be

$\sqrt{10}units$

Answer 2

Answer:

√10

Step-by-step explanation:

if the centre of the circle is (2,-3)

and (-1,-2) lies on the circle

then distance between the two points will give us the radius

by distance formula

√[2-(-1)]^2 + [-3-(-2)]^2

√9+1

√10=radius

hope it helps u

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