Points A, B, C, and D, in that order, lie on a line. If AB = 3 cm, AC = 4 cm, and BD = 8 cm, what is CD, in centimeters?	Answers
A) 7	B) 2	C) 3	D) 4	E) 5
Putting a value to each point, lets use the following:   A - 0   B - 3 (AB = 3)   C - 4 (AC = 4)   D - 11 (BD = 8)   CD is 11-4= 
<gadget id="calculator">11-4</gadget>
<output>7</output>
7.   7ns 7
<result>A</result>
Points A, B, C, and D, in that order, lie on a line. If AB = 3 cm, AC = 4 cm, and BD = 8 cm, what is CD, in centimeters?