Definition: Midpoint formula - The point that divides a line segment into two equal parts.

Example: A step-by-step calculation is shown for finding the midpoint of a triangle side and using it to determine other triangle properties.

Highlight: The page emphasizes the relationship between trigonometric functions and triangle properties, particularly in isosceles triangles.

Vocabulary: Point-direction form - A way to represent a line using a point on the line and a vector parallel to the line.

Example: One problem demonstrates how to check if point X(1,1,1) lies on a given line equation.

Highlight: The importance of understanding parametric equations of lines and their applications in 3D geometry is emphasized throughout this page.

Vocabulary: Isosceles triangle - A triangle with two sides of equal length.

Example: One problem involves determining if triangle BCF is isosceles by comparing the lengths of its sides.

Highlight: The page emphasizes the importance of understanding vector operations and their application in geometric calculations.