Question

In a ∆Abc, if AB=AC, and angle B =65° , find angle C and angle A.

Answer 1

angle A+B+C+D=180°
65°+65°=180°
170°=180°
10°

Answer 2

If AB=AC
then, 
     ∆ABC is an isosceles triangle
          ∠C= ∠B
            ∠C=65°
 Now,
       In ΔABC
we know that sum of all angles of a triangle is 180°
   ∠A+∠B+∠C=180°
   ∠A+65°+65°=180°
   ∠A+170°=180°
    ∠A=180°-170°
        ∠A=10°