Lesson 5 Proving Quadrilaterals Are Congruent Quadrilateral A
- Slides: 17
Lesson 5: Proving Quadrilaterals Are Congruent
Quadrilateral - A four-sided polygon Polygon – A plane figure that meets the following conditions: • Closed (has no openings) • All straight segments • Does not cross over itself.
Polygons are named by the number of sides they have. • • • 3 – Triangle 4 – Quadrilateral 5 – Pentagon 6 – Hexagon 7 – Heptagon • • • 8 - Octagon 9 - Nonagon 10 – Decagon 12 – Dodecagon 15 - Pentadecagon
Polygons can be described as convex or concave. • Convex – no line that contains a side of the polygon also contains a point in the interior of the polygon. • Concave – A polygon that is not convex.
• A REGULAR polygon is one that is equalilateral and equiangular. • A DIAGONAL is a segment that joins two non-consecutive vertices.
Theorems of Quadrilaterals Interior Angles of Quadrilateral – The sum of the interior angles of a quadrilateral is ______. We know that the sum of the interior angles of a triangle is _______. A quadrilateral can be divided into two triangles; therefore the sum of the interior angles is _____.
Parallelogram: A quadrilateral with both pairs of opposite sides parallel.
Theorems of Parallelograms: • If a quadrilateral is a parallelogram, then its opposite sides are congruent. Q P R S
Theorems of Parallelograms: • If a quadrilateral is a parallelogram, then its opposite angles are congruent. Q P R S
Theorems of Parallelograms: • If a quadrilateral is a parallelogram, then its consecutive angles are supplementary. Q P R S
Theorems of Parallelograms: • If a quadrilateral is a parallelogram, then its diagonals bisect each other. Q P R S
Let’s practice: F Ex: 1 G K J H
So, how do I prove a quadrilateral is a parallelogram? • 1. If the opposite sides of a quadrilateral are congruent, then it’s a parallelogram. • 2. If both pairs of opposite angles are congruent, then the quadrilateral is a parallelogram. • 3. If an angle is supplementary to both its consecutive angles, then it is a parallelogram.
So, how do I prove a quadrilateral is a parallelogram? (cont) • 4. If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. • 5. If one pair of opposite sides of a quadrilateral are congruent and parallel then the quadrilateral is a parallelogram.
- Insidan region jh
- Examples of parallelograms
- 6-1 classifying quadrilaterals
- Unit 5 lesson 2 triangle congruence by sss and sas
- Lesson 4-5 proving triangles congruent
- Unit 3 lesson 4 proving angles congruent
- Triangle congruence asa aas and hl
- Lesson 4-4 proving triangles congruent-sss sas
- Are adjacent angles congruent or supplementary
- 6-3 proving that a quadrilateral is a parallelogram
- Rhombus property
- Quadrilateral that has 2 pairs of parallel sides
- Congruent triangles sss sas asa aas
- Reflexive sides
- Unit 4 congruent triangles
- Classifying triangles maze
- Right triangle congruence theorem
- Quiz 4-2 congruent triangles