Question

To form a major arc two arms must subtend a minimum angle (in degree) of _________ at the center of the circle.

• A. ${180}^o$
• B. ${181}^o$
• C. ${360}^o$
• D. $0^o$

Answer 1

The correct option is B ${181}^o$

When two radii form an angle of $180$ degree at the center of a circle, it divides the circle into two equal hemispheres, forming two arc of equal length.


When the value of this angle changes the arcs form become unequal and the greater the angle subtended at the center, greater is the arc.

Hence to form a major arc, two arms must subtend a minium angle of $181$ degree at the center of the circle.