DAV Class 8 Maths Chapter 13 Value Based Questions
Introduction to Graphs Value Based Questions
A. Tick (✓) the correct option.
(a)
The point at which the x-axis and y-axis intersect on the cartesian plane is:
(i) abscissa (ii) origin (iii) ordinate (iv) none
Answer \( {\color{orange} (ii)} \ \color{red} \text{origin} \)
(ii)
If a point lies on the y-axis, its coordinates are:
(i) (x, 0) (ii) (0, 0) (iii) (x, y) (iv) (0, y)
Answer \( {\color{orange} (iv)} \ \color{red} (0, y) \)
(iii)
The distance of a point \( P(2, 3) \) from x-axis is:
(i) 3 units (ii) 2 units (iii) 5 units (iv) 1 unit
Answer \( {\color{orange} (i)} \ \color{red} \text{3 units} \)
Distance from x-axis = y-coordinate = 3 units.
(iv)
The distance of a point from y-axis is called:
(i) ordinate (ii) y-coordinate (iii) abscissa (iv) none
Answer \( {\color{orange} (iii)} \ \color{red} \text{abscissa} \)
B. Answer the following questions.
(a) Write down the coordinates of the origin.
Answer The coordinates of the origin are \( \color{red} (0, 0) \).
(b) What are the coordinates of a point which lies on the x-axis?
Answer Coordinates \( \color{red} (x, 0) \).
(c) What is the distance of the point \( C(4, 2) \) from the y-axis?
Answer The distance from the y-axis is: \( \color{red} 4 \text{ units} \).
(d) What is the distance between the points \( P(0,2) \) and \( Q(0,6) \)?
Solution
Both points lie on the same vertical line: x = 0.
Distance = \( 6 - 2 \implies \color{red} 4 \text{ units} \)
Answer \( \color{red} 4 \text{ units} \)
(e) If the vertices O, A, B of a square OABC are (0,0), (2,0), and (2,2), what are the coordinates of the fourth vertex C of the square?
Answer The fourth vertex is at \( \color{red} (0,2) \)
Given vertices:
- O = (0, 0)
- A = (2, 0)
- B = (2, 2)
- Therefore, C = (0, 2) completes the square.
2. Write the coordinates of each of the vertices of each polygon given below:
Answer
Coordinates of the vertices:
A(2, 0)
B(2, 2)
C(0, 2)
N(5, 0)
L(5, 4)
M(8, 2)
P(2, 6)
Q(4, 6)
R(5, 8)
S(3, 8)
3.
The runs scored by the Indian and Australian teams in first 10 overs are given below.
Draw a graph showing the data making the graphs on the same axes in each case.
Overs
I II III IV V VI VII VIII IX X
Runs (India)
3 4 6 5 7 8 10 5 6 4
Runs (Australia)
5 6 8 9 10 12 4 6 8 8
Answer
Scale:
x-axis: 1 unit = 1 over
y-axis: 1 unit = 1 run