Question 307236
a chord of a circle has length 4.2 cm and is 8cm from the center f the circle. what is the radius of the circle to the nearest hundereth

THE VERTICAL DISTANCE FROM THE CENTER TO THE CHORD = 8CM

the chord is bisected by this line at right angle.

so half of the chord = 4 cms.

half the chord , the line meeting the chord from the center of the circle and the radius form a right triangle. Hypotenuse is the radius.

one leg = 4cm
the other leg = 8 cm.

hypotenuse^2 = 4^2+8^2

hypotenuse ^2 = 16+64
hypotenuse ^2 = 80
Hypotenuse = sqrt 80
radius = 8.94 cm