It is a trapezoid in which the non-parallel sides are of the same length and subtend equal angles with the base. It can be viewed as an isosceles triangle whose apex has been removed by a line parallel to its base.
No, not every trapezoid is an isosceles trapezoid.
An isosceles trapezoid
If the two sides which are not parallel have equal lengths, then the trapezoid is called an isosceles trapezoid (standard trapezoid has unequal sides). The base angles in an isosceles trapezoid are equal in measurement, also I know that a trapezoid with two nonparallel sides the same length is called an isosceles trapezoid.
The base angles are congruent in an isosceles trapezoid
An isosceles triangle and a isosceles trapezoid.