Home Class 11 Applied Maths Chapter 15: Straight Lines

CBSE Applied Maths (2026-27) Unit VII: Coordinate Geometry Weightage: ~5 Marks in Unit

Chapter 15: Straight Lines

Master coordinate geometry tools, slope formulas, line equation forms, angles between lines, and perpendicular distance formulas.

4 Exercises

CBSE Curriculum Aligned

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Chapter Exercises & Topics

Select any exercise to access theory notes, formulas, practice drills, and mini tests.

Exercise 15.1 45 mins

Study Exercise Mini Test

Exercise 15.2 45 mins

Study Exercise Mini Test

Exercise 15.3 45 mins

Study Exercise Mini Test

Exercise 15.4 45 mins

Perpendicular distance of a point (x1, y1) from a line: d = |Ax1 + By1 + C| / √(A^2 + B^2)
Distance between two parallel lines: d = |C1 - C2| / √(A^2 + B^2)

Study Exercise Mini Test

Quick-glance formula revision for examination and numerical problem-solving:

$$d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$$
$$\text{Section Formula: } x = \frac{m x_2 + n x_1}{m+n}, \quad y = \frac{m y_2 + n y_1}{m+n}$$
$$\text{Area} = \frac{1}{2}|x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2)|$$
$$m = \tan \theta = \frac{y_2 - y_1}{x_2 - x_1}$$
$$\tan \theta = \left|\frac{m_2 - m_1}{1 + m_1 m_2}\right|$$
$$L_1 \parallel L_2 \iff m_1 = m_2, \quad L_1 \perp L_2 \iff m_1 m_2 = -1$$
$$y - y_1 = m(x - x_1), \quad y = mx + c, \quad \frac{x}{a} + \frac{y}{b} = 1$$
$$Ax + By + C = 0 \implies m = -\frac{A}{B}, \; c = -\frac{C}{B}$$
$$d = \frac{|A x_1 + B y_1 + C|}{\sqrt{A^2 + B^2}}$$
$$d_{\parallel} = \frac{|C_1 - C_2|}{\sqrt{A^2 + B^2}}$$