Final answer:
Without additional information or a visual representation of triangle ABC, it is impossible to definitively answer whether it is isosceles or determine the measure of angle ABC. We can rely on standard triangle properties such as the sum of interior angles being 180 degrees for further insights.
Step-by-step explanation:
The question pertains to understanding the properties of a triangle and applying mathematical concepts to determine its characteristics. Initially, without additional information about triangle ABC, we cannot determine whether AB equals BC (isosceles triangle), nor can we ascertain the measure of angle ABC. To be able to confirm whether angle ABC is 40° or if triangle ABC is isosceles, we require additional data or a figure accompanying the question. However, it can be established that if angle ABC is indeed 40° and side AB is equal to side BC, then triangle ABC is isosceles.
To answer this question accurately, information about specific measurements or a visual representation of triangle ABC is crucial. Without it, we can only provide a response based on standard triangle properties, such as the Pythagorean theorem to ascertain the relation between the sides if it is a right-angled triangle, and understanding that the sum of the interior angles in any triangle always equals 180 degrees.