The length of the base of an isosceles triangle is 12 inches. each base angle measures 50. which is a feasible plan to find the length of each congruent side of the triangle? justify each step

To get the congruent angles we shall use the sine rule since we have the length of at least 1 side and the values of the angles. 
Base length=12 inches
Base angles=50°
Third angle=180-(100)=80°
thus applying the sine rule we shall have:
a/sin A=b/sin B=c/sin C
thus we can get the congruent side as follows:
a/sin 50= 12/sin 80
a=(12 sin 50)/sin 80
a=9.334 inches
since the sides are congruent then the other congruent side will have a length of 9.334 inches