How do we use the properties of parallelograms?

Parallelogram - a quadrilateral with 2 pairs of parallel sides.



 -opposite angles are congruent

- diagonals bisects each other

- consecutive angles are supplementary

- opposite sides are congruent

How do we use triangle congruency?

Corresponding parts of congruent triangles are congruent.

How do we prove that triangles are congruent?

SSS - if 3 sides of a triangle are congruent to 3 sides of another triangle, then the 2 triangles are congruent .




SAS - if 2 sides of a triangle and the included angle are congruent to the 2 sides of another triangle and it's it's included angle, then the two triangles are congruent.






SAS - triangle are congruent if any two angles and their included side are equal in both triangles.

How are properties of medians and centroids?

Centroid - Intersecting of all 3 line segments of a triangle.

How do we use the Triangle inequality theorem?

The triangle inequality theorem are 3 numbers. If the 2 numbers add up to be greater than the third number in every way then you can create a triangle. If not then you either create a gap or a bridge.

Triangle inequality Theorem - the sum of any 2 sides of a triangle must be greater than the measure of the third side.

How do we use the triangle sum conjecture?

The triangle sum conjecture is the sum of the measures of the angles in every triangle is 180.

For example - if the measure of angle A in a triangle is 40 and the measure of angle B is 80, then the measure of angle C has to be 60 because it all adds up to measure of 180

How do we construct perpendicular bisector?

How do we construct an angle bisector?

 1st - Draw an angle

2nd - Use a compass and label an arch on the bottom line.

3rd - draw another arch on the top line with the same distance from the bottom arch ( do not move the arch or change the distance)

4th - place the arch where you last labeled it on the top then mark between the angle with the same distance.

5th - place the compass on the second (bottom) where you marked it first then create an arch between the angle

6th - draw a line starting at the vertex through and across into the arch