Radius of the circle is with center .

Redraw the figure as shown.

Area of the shaded region is sum of the areas of the triangle and sector.

Area of SAS triangles:

Two sides of the triangle are and angle is .

Area of the triangle .

Substitute corresponding values in the formula.

.

Find the area of the sector.

Area of the sector with central angle and radius is .

Therefore, .

.

.