1.We need two points to define a line.A different way to say this is that if you have two points, you will need at least a line to hold them.In this sense, what do you need at least three points to define?

A.three lines

B.a ray

C.an angle or a plane

D.a line or an angle

E.a line segment

F.a point

2.Two points define a line, but if there are two lines in a plane, and if they intersect somewhere, they "define" a single point.If there are two planes in space, and they intersect, what do they define?(Look at the walls of your room, where they meet. Imagine if there were no floor or ceiling, and the walls went up and down and side to side forever.What element describes where one wall meets another wall?)

A.a ray

B.a line

C.a point

D.a plane

E.a partridge

F.a pear tree

3.In the figure below, compare the two rays ry_BA and ry_CD.Which one is longer?

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