ICSE Class 10 Maths Selina Solutions Chapter 12: A quick overview of coordinate geometry and other key ideas, such as the origin, reflection of a point in several coordinate axes, and concerning a line, are provided in this chapter. Since Class 10 is a pivotal year in a student's life, they must have a firm grasp of the concepts taught in each chapter.
Students can benefit greatly from the ICSE Class 10 Maths Selina Solutions Chapter 12, which was developed by us to make the process simpler. After all, getting high marks in a subject like maths is beneficial. The solutions are provided in PDF format, allowing students to download them.ICSE Class 10 Maths Selina Solutions Chapter 12 PDF
1. Complete the following table:
Point | Transformation | Image | |
(a) | (5, -7) | _______________ | (-5, 7) |
(b) | (4, 2) | Reflection in x-axis | _____ |
(c) | _____ | Reflection in y-axis | (0, 6) |
(d) | (6, -6) | _______________ | (-6, 6) |
(e) | (4, -8) | _______________ | (-4, -8) |
Solution:
Point | Transformation | Image | |
(a) | (5, -7) | Reflection in origin | (-5, 7) |
(b) | (4, 2) | Reflection in x-axis | (4, -2) |
(c) | (0, 6) | Reflection in y-axis | (0, 6) |
(d) | (6, -6) | Reflection in origin | (-6, 6) |
(e) | (4, -8) | Reflection in y-axis | (-4, -8) |
2. A point P is its own image under the reflection in a line l. Describe the position of point the P with respect to the line l.
Solution:
As, the image of the point P is the same point under the reflection in the line l we can say, point P is an invariant point. Thus, the position of point P remains unaltered.3. State the co-ordinates of the following points under reflection in x-axis:
(i) (3, 2)
(ii) (-5, 4)
(iii) (0, 0)
Solution:
(i) (3, 2) The co-ordinates of the given point under reflection in the x-axis are (3, -2). (ii) (-5, 4) The co-ordinates of the given point under reflection in the x-axis are (-5, -4). (iii) (0, 0) The co-ordinates of the given point under reflection in the x-axis are (0, 0).4. State the co-ordinates of the following points under reflection in y-axis:
(i) (6, -3)
(ii) (-1, 0)
(iii) (-8, -2)
Solution
(i) (6, -3) The co-ordinates of the given point under reflection in the y-axis are (-6, -3). (ii) (-1, 0) The co-ordinates of the given point under reflection in the y-axis are (1, 0). (iii) (-8, -2) The co-ordinates of the given point under reflection in the y-axis are (8, -2).5. State the co-ordinates of the following points under reflection in origin:
(i) (-2, -4)
(ii) (-2, 7)
(iii) (0, 0)
Solution:
(i) (-2, -4) The co-ordinates of the given point under reflection in origin are (2, 4). (ii) (-2, 7) The co-ordinates of the given point under reflection in origin are (2, -7). (iii) (0, 0) The co-ordinates of the given point under reflection in origin are (0, 0).6. State the co-ordinates of the following points under reflection in the line x = 0:
(i) (-6, 4)
(ii) (0, 5)
(iii) (3, -4)
Solution:
(i) (-6, 4) The co-ordinates of the given point under reflection in the line x = 0 are (6, 4). (ii) (0, 5) The co-ordinates of the given point under reflection in the line x = 0 are (0, 5). (iii) (3, -4) The co-ordinates of the given point under reflection in the line x = 0 are (-3, -4).7. State the co-ordinates of the following points under reflection in the line y = 0:
(i) (-3, 0)
(ii) (8, -5)
(iii) (-1, -3)
Solution:
(i) (-3, 0) The co-ordinate of the given point under reflection in the line y = 0 is (-3, 0). (ii) (8, -5) The co-ordinate of the given point under reflection in the line y = 0 is (8, 5). (iii) (-1, -3) The co-ordinate of the given point under reflection in the line y = 0 is (-1, 3).8. A point P is reflected in the x-axis. Co-ordinates of its image are (-4, 5).
(i) Find the co-ordinates of P.
(ii) Find the co-ordinates of the image of P under reflection in the y-axis.
Solution:
(i) As, M x (-4, -5) = (-4, 5) Hence, the co-ordinates of P are (-4, -5). (ii) Co-ordinates of the image of P under reflection in the y-axis (4, -5).9. A point P is reflected in the origin. Co-ordinates of its image are (-2, 7).
(i) Find the co-ordinates of P.
(ii) Find the co-ordinates of the image of P under reflection in the x-axis.
Solution:
(i) As, M O (2, -7) = (-2, 7) Hence, the co-ordinates of P are (2, -7). (ii) Co-ordinates of the image of P under reflection in the x-axis (2, 7)1. Attempt this question on graph paper.
(a) Plot A (3, 2) and B (5, 4) on graph paper. Take 2 cm = 1 unit on both the axes.
(b) Reflect A and B in the x-axis to A’ and B’ respectively. Plot these points also on the same graph paper.
(c) Write down:
(i) the geometrical name of the figure ABB’A’;
(ii) the measure of angle ABB’;
(iii) the image of A” of A, when A is reflected in the origin.
(iv) the single transformation that maps A’ to A”.
Solution:
(c) (i) From the graph, it’s clearly seen that ABB’A’ is an isosceles trapezium. (ii) The measure of angle ABB’ is 45°. (iii) A” = (-3, -2) (iv) Single transformation that maps A’ to A” is the reflection in y-axis.2. Points (3, 0) and (-1, 0) are invariant points under reflection in the line L 1 ; points (0, -3) and (0, 1) are invariant points on reflection in line L 2 .
(i) Name or write equations for the lines L 1 and L 2 .
(ii) Write down the images of the points P (3, 4) and Q (-5, -2) on reflection in line L 1 . Name the images as P’ and Q’ respectively.
(iii) Write down the images of P and Q on reflection in L 2 . Name the images as P” and Q” respectively.
(iv) State or describe a single transformation that maps P’ onto P”.
Solution:
(i) We know that, every point in a line is invariant under the reflection in the same line. As the points (3, 0) and (-1, 0) lie on the x-axis. Thus, (3, 0) and (-1, 0) are invariant under reflection in x-axis. Therefore, the equation of line L 1 is y = 0. Similarly, (0, -3) and (0, 1) are also invariant under reflection in y-axis. Therefore, the equation of line L 2 is x = 0. (ii) P’ = Image of P (3, 4) in L 1 = (3, -4) And, Q’ = Image of Q (-5, -2) in L 1 = (-5, 2) (iii) P” = Image of P (3, 4) in L 2 = (-3, 4) And, Q” = Image of Q (-5, -2) in L 2 = (5, -2) (iv) Single transformation that maps P’ onto P” is reflection in origin.3. (i) Point P (a, b) is reflected in the x-axis to P’ (5, -2). Write down the values of a and b.
(ii) P” is the image of P when reflected in the y-axis. Write down the co-ordinates of P”.
(iii) Name a single transformation that maps P’ to P”.
Solution:
(i) As, M x (x, y) = (x, -y) P’ (5, -2) = reflection of P (a, b) in x-axis. Hence, the co-ordinates of P are (5, 2). Thus, a = 5 and b = 2. (ii) P” = image of P (5, 2) reflected in y-axis = (-5, 2) (iii) Single transformation that maps P’ to P” is the reflection in origin.4. The point (-2, 0) on reflection in a line is mapped to (2, 0) and the point (5, -6) on reflection in the same line is mapped to (-5, -6).
(i) State the name of the mirror line and write its equation.
(ii) State the co-ordinates of the image of (-8, -5) in the mirror line.
Solution:
(i) We know that, reflection of a point (x, y) in y-axis is (-x, y). So, the point (-2, 0) when reflected in y-axis is mapped to (2, 0). Hence, the mirror line is the y-axis and it’s equation is x = 0. (ii) The co-ordinates of the image of (-8, -5) in the mirror line (i.e., y-axis) are (8, -5).5. The points P (4, 1) and Q (-2, 4) are reflected in line y = 3. Find the co-ordinates of P’, the image of P and Q’, the image of Q.
Solution:
6. A point P (-2, 3) is reflected in line x = 2 to point P’. Find the coordinates of P’.
Solution:
7. A point P (a, b) is reflected in the x-axis to P’ (2, -3). Write down the values of a and b. P” is the image of P, reflected in the y-axis. Write down the co-ordinates of P”. Find the co-ordinates of P”’, when P is reflected in the line, parallel to y-axis, such that x = 4.
Solution:
8. Points A and B have co-ordinates (3, 4) and (0, 2) respectively. Find the image:
(a) A’ of A under reflection in the x-axis.
(b) B’ of B under reflection in the line AA’.
(c) A” of A under reflection in the y-axis.
(d) B” of B under reflection in the line AA”.
Solution:
Detailed Solutions : Selina Solutions break down each problem into manageable steps, helping students understand the process of reflecting shapes over lines or points.
Visual Aids : Problems often include diagrams which make abstract concepts like symmetry and congruence more tangible.
2. Improved Problem-Solving SkillsPractice Problems : Access to a variety of problems with solutions helps students practice and reinforce their understanding of reflection.
Step-by-Step Guidance : Detailed solutions demonstrate methods and strategies to solve similar problems independently.
3. Enhanced Learning and RetentionReinforcement of Key Ideas : Repeated exposure to reflection problems and their solutions helps in better retention of concepts.
Error Correction : Reviewing solutions can help students identify and learn from mistakes, improving their problem-solving skills.
4. Efficient Study ToolQuick Reference : Selina Solutions serve as a quick reference to verify answers and understand the correct approach.
Time Management : They save time by providing instant feedback on solutions and methods, which is especially helpful during revision.
5. Preparation for ExamsExam Pattern Familiarity : By practicing with Selina Solutions, students become familiar with the types of problems that may appear in exams.
Confidence Building : Mastery of reflection problems through practice boosts confidence and reduces exam anxiety.