1. Prove that a given quadrilateral is a rectangle, square or rhombus
LT 6.5

2. Parent: Your geometry teacher thinks you need extra homework
Parent: Your geometry teacher thinks you need extra homework. Student: Tell her I want proof!
Math Humor

3. Conditions for Rectangles

4. A manufacturer builds a mold for a desktop so that , , and mABC = 90°
A manufacturer builds a mold for a desktop so that , , and mABC = 90°. Why must ABCD be a rectangle?
Example 1:

5. Conditions for Rhombuses

6. Since a square is a parallelogram with all properties of a rectangle and a rhombus Parallelogram yes opp sides are congruent Rectangle yes one right angle Rhombus yes diagonals are perpendicular
Yes it is a square

7. Determine if the conclusion is valid
Determine if the conclusion is valid. If not, tell what additional information is needed to make it valid. Use the diagonals to determine whether a parallelogram with the given vertices is a rectangle, rhombus, or square. Give all names that apply. A(0,2), B(3, 6), C(8, 6), D(5, 2)
Example 3:

8. A(0,2), B(3, 6), C(8, 6), D(5, 2)