Question

A chord of a circle 9cm long if it's distance of the centre of the circle is 5 cm calculate the radius of the circle

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Answer 1

considering the distance between the center of the circle and the chord is perpendicular, pythagorean theorem can be applied to calculate the radius of the circle.

`r^2=a^2+b^2` , r=radius, a=half of the chord length, b the distance between the center of the circle and the center of the chord

`r^2=(4.5cm)^2+(5cm)^2\\r^2=20.25cm^2+25cm^2\\r^2=45.25cm^2\\r=√(45.25cm^2)\\r=6.7268cm`