Answer:
AB
Explanation:
the angles DCB and ACB are supplementary angles (together 180°).
simply because the sum of all angles around a single point on one side of a line is suggests 180° (it represents a half-circle).
so, the inner angle ACB is
ACB = 180 - 50 = 130°
because the sum of all angles in a triangle is also always 180°, there are only 50° left for the other 2 angles.
so, the inner angle at C is clearly the largest angle in the triangle ABC.
the larger an angle, the longer the opposing side.
the largest angle has the longest opposing side in the triangle.
the opposing side of the inner angle C is AB. and that is therefore the longest side in the triangle ABC.