Diameter of a circle is 20 cm. Length of a chord AB is 10 cm. What will be the angle made by this chord at the center of this circle ?

60 degree

Concept Used

Radius = \(\frac{Diameter}{2}\)

2. In an equilateral triangle, since the three sides are equal therefore the three angles, opposite to the equal sides are equal in measure.

Calculation

OA = OB = AB = 10 cm

\(\Delta \)OAB is an equilateral triangle.

So, \(\angle\)OAB = \(\angle\)OBA = \(\angle\)AOB = \(\frac{180}{3}\) = \({60}^\circ\)

Therefore, the angle made by this chord at the center of this circle = \({60}^\circ\).