2023 · Q35
Two parallel chords AB and CD of a circle are of lengths 60 cm and 80 cm respectively. They are on the same side of the centre O and 10 cm apart. What is the diameter of the circle?
Elementary MathematicsCircles
- A120 cm
- B110 cm
- C100 cm
- D90 cm
Explanation
30^2+d1^2=40^2+d2^2=r^2, |d1-d2|=10 gives d1+d2=70, so d1=40,d2=30,r=50; diameter 100 cm. Option (c).