Coordinate Geometry
NCERT Solutions • Class 9 Maths • Chapter 3Exercise 3.2
1. Write the answer of each of the following questions:
(i) What is the name of horizontal and the vertical lines drawn to determine the position of any point in the Cartesian plane?
• Horizontal line: X-axis
• Vertical line: Y-axis
• Horizontal line: X-axis
• Vertical line: Y-axis
(ii) What is the name of each part of the plane formed by these two lines?
The lines divide the plane into four parts known as Quadrants (I, II, III, and IV).
The lines divide the plane into four parts known as Quadrants (I, II, III, and IV).
(iii) Write the name of the point where these two lines intersect.
The point of intersection is called the Origin. Its coordinates are $(0, 0)$.
The point of intersection is called the Origin. Its coordinates are $(0, 0)$.
2. See Fig. 3.14, and write the following:
(i) The coordinates of B.
Point B is in the 2nd quadrant. Distance from Y-axis = -5, Distance from X-axis = 2.
Answer: (-5, 2)
Point B is in the 2nd quadrant. Distance from Y-axis = -5, Distance from X-axis = 2.
Answer: (-5, 2)
(ii) The coordinates of C.
Point C is in the 4th quadrant. Distance from Y-axis = 5, Distance from X-axis = -5.
Answer: (5, -5)
Point C is in the 4th quadrant. Distance from Y-axis = 5, Distance from X-axis = -5.
Answer: (5, -5)
(iii) The point identified by the coordinates (–3, –5).
Looking at the 3rd quadrant (x < 0, y < 0), the point at x = -3 and y = -5 is E.
Answer: Point E
Looking at the 3rd quadrant (x < 0, y < 0), the point at x = -3 and y = -5 is E.
Answer: Point E
(iv) The point identified by the coordinates (2, – 4).
Looking at the 4th quadrant (x > 0, y < 0), the point at x = 2 and y = -4 is G.
Answer: Point G
Looking at the 4th quadrant (x > 0, y < 0), the point at x = 2 and y = -4 is G.
Answer: Point G
(v) The abscissa of the point D.
Point D is at coordinates $(6, 2)$. The abscissa is the x-coordinate.
Answer: 6
Point D is at coordinates $(6, 2)$. The abscissa is the x-coordinate.
Answer: 6
(vi) The ordinate of the point H.
Point H is at coordinates $(-5, -3)$. The ordinate is the y-coordinate.
Answer: -3
Point H is at coordinates $(-5, -3)$. The ordinate is the y-coordinate.
Answer: -3
(vii) The coordinates of the point L.
Point L lies on the Y-axis (so x = 0) at y = 5.
Answer: (0, 5)
Point L lies on the Y-axis (so x = 0) at y = 5.
Answer: (0, 5)
(viii) The coordinates of the point M.
Point M lies on the X-axis (so y = 0) at x = -3.
Answer: (-3, 0)
Point M lies on the X-axis (so y = 0) at x = -3.
Answer: (-3, 0)