Question 694176
I'll do the first six to get you started.


1.If three points are collinear, then they are coplanar ... <font color="red">false</font> (think of a line going through a plane but the line isn't all in the plane)


2.Any two points are collinear ... <font color="red">true</font> by definition


3.Given two points, there is more than one plane containing them ... <font color="red">true</font>, you need 3 points to uniquely determine a plane


4. The bisector of the vertex angle of an isosceles triangle bisects the base and is perependicular to the base ... <font color="red">true</font>, this takes a while to explain and prove, but it can be done.


5. The base angles of an isosceles triangle are acute ... <font color="red">true</font>, a picture may help see this


6. An altitude of a triangle lies in the interior of the triangle ... <font color="red">false</font>, this is sometimes the case, but sometimes not. Think obtuse triangles.


I'll let you do the rest.


7. If three triangles have unequal measures, then no two sides of the triangle are congruent
8. Every right angle has two acute angles
9. The longest side of any triangle is called the hypotenuse
10. The median of a triangle bisects the side to which its drawn
11. Each side of an angle is a ray
12. The diagonals of a square are perpendicular to each other.