△BCD is a special right triangle called a " 30-60-90 triangle " because its angles are 30°, 60°, and 90°.
In every 30-60-90 triangle, if the side opposite the 30° angle is n , then
the side opposite the 60° angle is n√3 and the side opposite the 90° angle is 2n
In △BCD, the side opposite the 30° is 12 , so
the side opposite the 60° angle is 12√3 and the side opposite the 90° angle is 2(12) .
So.....
BC = 12√3
BD = 2(12) = 24
height of the triangle = 12√3 cm
area of triangle = ( 1/2 )( base )( height )
area of triangle = ( 1/2 )( 12 )( 12√3 ) cm2 I'll let you simplify this.