Step 1
An isosceles triangle is a triangle that has two sides of equal length. Sometimes it is specified as having exactly two sides of equal length, and sometimes as having at least two sides of equal length.
Step 2
Since the sides of an isosceles triangle are equal it follows that the base angles are equal too. The vertex angle = 98°. The sum of angles in a triangle is 180°.
Therefore, if the base angles are both x,
Therefore,