Chapter 5 Geometry Mr. McKendrick Name: ______________________ Date: _______________________ Period: ______________________ Always, Sometimes, Never Practice Write if the statement is always, sometimes, or never true. 1. Opposite angles of an isosceles trapezoid are supplementary. 2. The consecutive sides of a parallelogram are congruent. 3. The diagonals of a rectangle bisect the angles. 4. Exactly one pair of opposite sides of a trapezoid is congruent. 5. All angles of a parallelogram are congruent. 6. Exactly one pair of opposite sides of a trapezoid is parallel. 7. All sides of a kite are congruent. 8. All angles of a trapezoid are congruent. 9. The diagonals of square are perpendicular bisectors of each other. 10. A rectangle is a kite. 11. A rhombus is a square. 12. A trapezoid is a rhombus. 13. A square is a parallelogram. 14. All four sides of a parallelogram are congruent. 15. If one diagonal of a quadrilateral is the perpendicular bisector of the other, then the quadrilateral is a rhombus. 16. If the diagonals of a quadrilateral are congruent, then the quadrilateral is a rectangle. 17. If one pair of opposite sides of a quadrilateral are both parallel and congruent, then the quadrilateral is a trapezoid. 18. If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. Always, Sometimes, Never Solutions 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. Opposite angles of an isosceles trapezoid are supplementary. A Since the lower base angles are congruent and the upper base angles are congruent, any pair of opposite angles are supplementary. The consecutive sides of a parallelogram are congruent. S The consecutive sides are congruent only if the parallelogram is a rhombus (or a square). The diagonals of a rectangle bisect the angles. S Diagonals bisecting angles is a property of a rhombus, so this would only happen if the rectangle was a square. Exactly one pair of opposite sides of a trapezoid is congruent. S This would only happen if the trapezoid was an isosceles trapezoid. All angles of a parallelogram are congruent. S This would only happen if the parallelogram was a rectangle (or a square). Exactly one pair of opposite sides of a trapezoid is parallel. A This is the definition of a trapezoid. All sides of a kite are congruent. S This would only happen if the kite was a rhombus. All angles of a trapezoid are congruent. N If all of the angles in a quadrilateral were congruent, the figure would be a rectangle. But a trapezoid can’t be a rectangle. The diagonals of square are perpendicular bisectors of each other. A This is a property of a rhombus, so it would also be a property of a square. A rectangle is a kite. S A rectangle can be a kite…when the kite is a rhombus. A rectangle is a kite when the rectangle is a square. A rhombus is a square. S A rhombus can be a square, but it doesn’t have to be. A trapezoid is a rhombus. N A trapezoid can’t be a rhombus because a rhombus is a parallelogram. A trapezoid can’t be a parallelogram. A square is a parallelogram. A A square is a type of rectangle, which is a type of parallelogram. All four sides of a parallelogram are congruent. S All four sides can be congruent (it would be a rhombus), but they don’t have to be. If one diagonal of a quadrilateral is the perpendicular bisector of the other, then the quadrilateral is a rhombus. S This proves that the figure is a kite. But a rhombus is a type of kite, so this is sometimes. If the diagonals of a quadrilateral are congruent, then the quadrilateral is a rectangle. S If the diagonals are congruent, then the quadrilateral can be a rectangle, square, or isosceles trapezoid. If one pair of opposite sides of a quadrilateral is both parallel and congruent, then the quadrilateral is a trapezoid. N This proves that a quadrilateral is a parallelogram, and a parallelogram can’t be a trapezoid. If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. A This is one of the ways to prove a quadrilateral is a parallelogram.