Chapter 7: Coordinate Geometry

Math • Class 10

Download PDF

Loading PDF...

Chapter Analysis

Intermediate16 pages • English

Quick Summary

This chapter introduces the concepts of coordinate geometry, focusing on distance formula, section formula, and applications of coordinate geometry. It elaborates on how to find the distance between two points given their coordinates and how to determine the coordinates of a point dividing a line segment in a given ratio. Various examples and exercises solidify understanding, making these concepts accessible and practical.

Key Topics

  • Distance formula
  • Section formula
  • Midpoint formula
  • Collinearity of points
  • Area of a triangle using coordinates
  • Properties of parallelograms in coordinate geometry

Learning Objectives

  • Understand and apply the distance formula to find the distance between two points.
  • Utilize the section formula to find coordinates dividing a line segment in a given ratio.
  • Determine the midpoint of a line segment using its endpoints.
  • Apply knowledge of coordinate geometry to verify collinearity and properties of triangles.
  • Solve problems related to the division of line segments both internally and externally.
  • Use coordinate geometry to prove properties of geometric shapes like parallelograms.

Questions in Chapter

Find the distance between the following pairs of points: (2, 3), (4, 1) and (– 5, 7), (– 1, 3).

Page 106

If Q(0, 1) is equidistant from P(5, –3) and R(x, 6), find the values of x. Also find the distances QR and PR.

Page 106

Find a relation between x and y such that the point (x, y) is equidistant from the point (3, 6) and (– 3, 4).

Page 106

Additional Practice Questions

Determine the mid-point of the line segment joining the points (6, -3) and (-4, 7).

easy

Answer: The mid-point is ((6 + (-4))/2, (-3 + 7)/2) = (1, 2).

A triangle has vertices at (1, 2), (3, 4), and (5, 6). Calculate the perimeter of the triangle.

medium

Answer: Using the distance formula for each side: AB = √((3-1)^2 + (4-2)^2) = √8, BC = √((5-3)^2 + (6-4)^2) = √8, CA = √((5-1)^2 + (6-2)^2) = √32. The perimeter = √8 + √8 + √32 ≈ 4√2 + 4√2 + 5√2 = 13√2.

What are the coordinates of a point that divides the line segment joining (2, 1) and (-2, -3) externally in the ratio 2:3?

hard

Answer: Using the section formula for external division, the coordinates are ((2*-2 + 3*2)/(2-3), (2*-3 + 3*1)/(2-3)) = ((-4 + 6)/-1, (-6 + 3)/-1) = (-2, 3).

If a quadrilateral has vertices at (1, 2), (3, 5), (6, 1), and (4, -2), is it a parallelogram?

medium

Answer: Calculate the midpoints of diagonals to verify if they bisect each other: M1 for AC = ((1+6)/2, (2+1)/2) = (3.5, 1.5), M2 for BD = ((3+4)/2, (5-2)/2) = (3.5, 1.5). Since the midpoints are equal, it is a parallelogram.

Verify if the points (3, 3), (6, 6), (9, -3) are collinear.

easy

Answer: The points are collinear if the area of the triangle they form is zero. Using the determinant method, the area is 0.5*[3(6+3) + 6(-3-3) + 9(3-6)] = 0. Hence, they are collinear.