Description: The topic explores conditions, equations, and properties when two lines form a straight-line pair.

Description: It examines intersection, angle conditions, and formula derivations for lines forming a two-line pair.

Description: Solution of Ex.4.1 Part I

Description: Solution of Ex.4.1 Part II

Description: Solution of Ex.4.2 Part I

Description: Solution of Ex.4.2 Part II & General Second Degree Equation in x and y

Description: Solution of Ex.4.3 Part I

Description: Solution of Ex.4.3 Part II