The sides BC, CA, AB of triangle ABC have 3, 4, 5 interior points respectively on them. How many triangles can be formed using these points as vertices.	Choose the correct choice:	A) 200	B) 205	C) 400	D) 410	E) 420
Total points: 3+4+5= 
<gadget id="calculator">3+4+5</gadget>
<output>12</output>
12;   Any 3 points out of 12 but those which are collinear will form a triangle, so C312−(C33+C34+C35)=220−(1+4+10)=205C123−(C33+C43+C53)=220−(1+4+10)=205.   Answer: 205.
<result>B</result>
The sides BC, CA, AB of triangle ABC have 3, 4, 5 interior points respectively on them. How many triangles can be formed using these points as vertices.