rectangle and parallelogram
square, rectangle and an isosceles trapezoid.
Rectangles
rectangle and parallelogram
A square
rectangle and parallelogram
square, rectangle and an isosceles trapezoid.
square
Rectangles
Not generally.
Most quadrilaterals do not.
rectangle and parallelogram
there is nothing listed
Most quadrilaterals will not have congruent diagonals: rectangles (incl squares) and isosceles trapezium are the exception.
A square
Parallelograms or isosceles trapezium.
the diagonals of a trepazoid always congruent?