00:01
All right, so we're going to draw some quadrilaterals.
00:06
So we want them to have opposite sides or parallel.
00:10
So we can draw any kind of quadrororalogram we want.
00:14
We can have a square.
00:17
We could have a rectangle.
00:19
We could have a parallelogram.
00:22
We could have a rhombus.
00:25
And we could change the sizes of them.
00:29
We could make this parallelogram really.
00:33
Tall, we could make the rectangle really skinny.
00:40
Now you could find the angle measures of all these quadrilaterals that you drew.
00:49
The rectangles and the squares are easy because you know they're 90 degrees, but you're going to find that no matter the parallelogram that you draw, that these quadrilaterals have opposite angles that are congruent to each other.
01:10
So what that means is that if it's a parallelogram, the opposite angles are congruent.
01:22
So we're going to now prove the converse of that.
01:27
So we're going to try to prove that if opposite angles of a.
01:40
Quadrilateral are congruent, then opposite sides are parallel.
01:59
Great.
02:01
So we have to figure out what our given and our prove are...