2014 · Q79
The chord of an arc of a circle is of length x, the height of the arc is y and the radius of the circle is z. Which one of the following is correct?
Elementary MathematicsCircles
- Ay(2z − y) = x²
- By(2z − y) = 4x²
- C2y(2z − y) = x²
- D4y(2z − y) = x²
Explanation
(x/2)² + (z − y)² = z² gives x²/4 = 2zy − y², i.e. x² = 4y(2z − y).