2018 · Q95
In the figure given below, AB is the diameter of the circle whose centre is at O. Given that ECD = EDC = 32^{}, then CEF and COF respectively are
Elementary MathematicsCircles
- A32° , 64°
- B64° , 64°
- C32° , 32°
- D64° , 32°
Explanation
Angle CEF is exterior to triangle ECD: angle CEF = 32 + 32 = 64 degrees. Angle COF is the central angle subtending the same arc as the inscribed angle CDF = 32 degrees, so angle COF = 2 x 32 = 64 degrees. Hence option B.