Question

A circle has a radius of 6 cm. Find the length of that chord which is at a distance of 4 cm from the center.

Hint:

Use Pythagoras theorem to find chord length when perpendicular from center is given.

Answer 1

Using the perpendicular bisector theorem:
\[ L = 2\sqrt{r^2 - d^2}. \] \[ L = 2\sqrt{6^2 - 4^2}. \] \[ = 2\sqrt{36 - 16} = 2\sqrt{20} = 2 \times 2\sqrt{5} = 4\sqrt{5} \approx 8.94 \text{ cm}. \]