Class 10 · Chapter 7

Coordinate Geometry

Distance formula, section formula, area of a triangle from coordinates.

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Mathematics · Class 10 (2026-27)
Tip: NCERT updated the syllabus for 2026-27. The links above open the latest edition on the official portal — chapter titles and numbering may differ from the notes shown here.
Detailed theory
The plane is divided into 4 quadrants by the xx- and yy-axes at the origin. A point P(x,y)P(x, y) has abscissa xx (distance from yy-axis) and ordinate yy (from xx-axis). Signs of coordinates identify the quadrant.
Key concepts & formulas
01
Distance =(x2−x1)2+(y2−y1)2=\sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}.
02
Section formula (internal, ratio m:nm:n): (mx2+nx1m+n,  my2+ny1m+n)\left(\dfrac{mx_2+nx_1}{m+n},\; \dfrac{my_2+ny_1}{m+n}\right).
03
Midpoint: (x1+x22,  y1+y22)\left(\dfrac{x_1+x_2}{2},\; \dfrac{y_1+y_2}{2}\right).
04
Area of triangle =12∣x1(y2−y3)+x2(y3−y1)+x3(y1−y2)∣=\tfrac{1}{2}\big|x_1(y_2-y_3) + x_2(y_3-y_1) + x_3(y_1-y_2)\big|.
05
Collinear: area of triangle =0= 0.
06
Distance from origin: x2+y2\sqrt{x^2 + y^2}.
Gyaan Maths — CBSE Class 6-12, built for board-toppers.
v1.1 · Sept 2026