An Isosceles triangle has two sides and two angles to be congruent or equal.
Let the two congruent angles be x° degrees, then the third side which is 57° greater than the congruent angles would measure (x+57°).
SKETCH
The sum of angles in a triangle is 180°. Hence,
[tex]\begin{gathered} x+x+(x+57)=180^0 \\ 3x+57=180^0 \\ 3x=180-57 \\ 3x=123 \\ x=\frac{123}{3} \\ x=41^0 \\ \therefore(x+57)=41^0+57^0=98^0 \end{gathered}[/tex]
Therefore, the measure of all three angles are: 41,⁰ 41⁰, and 98⁰
