A quadrilateral is a . . . . . . . . . . . . . If a pair of opposite sides are equal and parallel.

Are the opposite sides of a kite equal ?

Prove: In a parallelogram, opposite sides are equal.

A rhombus is a quadrilateral with . . . . . . . . Of equal length.

Are the opposite angles of a rhombus equal ?

If two consecutive angles of cyclic quadrilateral are congruent, then prove that one pair of opposite sides is congruent and other is parallel.

Two polygons with same number of sides are ........................ if their corresponding angles are equal and corresponding sides are equal.

All sides of a . . . . . . . . Are equal and all angles are right angles.

Prove that in a tetrahedron if two pairs of opposite edges are perpendicular , then the third pair is also perpendicular.

The two adjacent sides of a cyclic quadrilateral are 2a n d5 and the angle between them is 60^0dot If the area of the quadrilateral is 4sqrt(3) , find the remaining two sides.

The midpoint of two opposite sides of a quadrilateral and the midpoint of the diagonals are the vertices of a parallelogram. Prove that using vectors.