Question 740309
Draw a perpendicular from O to one of its base. SAY OT.

the triangle formed is 30-60-90 

with hypotenuse as 10. 

side opposite to 60 deg is {{{(sqrt(3)/2)*hypotenuse}}}

the side will be {{{5sqrt(3)}}}

the chord of the circle is the side of the triangle.

side of triangle = 2*{{{5sqrt(3)}}}  = {{{10sqrt(3)}}}

Area of equilateral triangle = {{{(sqrt(3)/4 )* s^2}}}

s= {{{10sqrt(3)}}}

AREA =  {{{((sqrt(3))/4 )* (10sqrt(3))^2}}}=129.9


Area of circle = {{{ pi * r^2}}}

=3.14 *10*10

=314 sq units

the difference is the area of shaded portion
area of circle - area of triangle