Rectangle
never
A quadrilateral never has exactly 3 congruent angles. It can have none, two, two pairs of two, or four.
Sometimes
sometimes
sometimes
yes it always hat two
Yes, that is what a trapezoid is. * * * * * NO. The parallel sides of a trapezium are never congruent. So a trapezium cannot have 4 congruent sides. So the answer to the question is "No, it is not".
There are two pairs of congruent base angles in an isosceles trapezoid.
No. For any random quadrilateral, they are actually "never" congruent. The probability of the sides being so is infinitely less than the probability they will not be.
A scalene triangle is a triangle in which all three sides and all three angles are different. Therefore two angles of a scalene triangle are NEVER congruent.
True. A scalene does NOT have any congruent angles.
sometimes