Question 1087174
Put center of the circle at the origin and make the chord 30 cm parallel to the x axis, and above the x-axis.  Endpoints of this chord are (-15, 20) and (15, 20).


Radius:
{{{r^2=15^2+20^2}}}
{{{r^2=225+400}}}
{{{r^2=625}}}
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{{{x^2+y^2=625}}}



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Calculate the length of a chord which is 24cm from the centre.
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Endpoints of this chord,  can be (x, 24) and (-x, 24).
{{{x^2=625-y^2}}}
{{{x=sqrt(625-24^2)}}}
{{{x=sqrt(49)=7}}}
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Length of chord,  {{{2*7=highlight(14)}}}
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