IMOClass 10 › Chapter Test

Coordinate Geometry — Chapter Test

00:00
Q1
The distance of any point from itself is:
A point coincides with itself, so the distance is 0.
Q2
The distance between (7, 1) and (3, 4) is:
√((7 − 3)² + (1 − 4)²) = √(16 + 9) = 5.
Q3
The distance between the points (0, 0) and (3, 4) is:
xyOO(0,0)(3,4)
Distance = √(3² + 4²) = √25 = 5.
Q4
The area of the quadrilateral with vertices (1, 1), (7, 1), (7, 5) and (1, 5) is:
xyO(1,1)(7,1)(7,5)(1,5)
It is a 6 by 4 rectangle, so the area is 6 × 4 = 24 sq units.
Q5
Three sensors are placed at (0, 0), (4, 0) and (2, 6). The area they enclose is:
xyOO(4,0)(2,6)
Base 4 (along the x-axis) and height 6, so area = ½ × 4 × 6 = 12.
Q6
The distance of the point (5, 12) from the origin is:
xyOO(5,12)
√(5² + 12²) = √169 = 13.
Q7
The point (−3, 5) lies in which quadrant?
xyO(−3, 5)
Negative x with positive y places it in Quadrant II.
Q8
The point that divides the join of (1, 2) and (4, 8) in the ratio 1 : 2 internally is:
xyOA(1,2)B(4,8)P
Using the section formula: ((1·4 + 2·1)/3, (1·8 + 2·2)/3) = (2, 4).
Q9
A surveyor marks a plot with corners (0, 0), (4, 0), (4, 3) and (0, 3). Its perimeter is:
xyOO(4,0)(4,3)(0,3)
It is a 4 by 3 rectangle, so perimeter = 2(4 + 3) = 14 units.
Q10
The reflection of (3, 5) in the y-axis is:
Reflecting in the y-axis changes the sign of the x-coordinate.
Q11
The midpoint of the segment joining (2, 4) and (6, 8) is:
xyO(2,4)(6,8)(4,6)
Midpoint = ((2 + 6)/2, (4 + 8)/2) = (4, 6).
Q12
A garden is a triangle with corners at (0, 0), (6, 0) and (6, 8) on a grid (metres). Its area is:
xyOO(6,0)(6,8)
Right-angled with legs 6 and 8, so area = ½ × 6 × 8 = 24 m².
Q13
The area of the triangle with vertices (1, 1), (2, 3) and (4, 5) is:
xyO(1,1)(2,3)(4,5)
Area = ½|1(3 − 5) + 2(5 − 1) + 4(1 − 3)| = ½|−2 + 8 − 8| = 1.
Q14
The points (3, 0), (6, 4) and (−1, 3) are the vertices of:
xyO(3,0)(6,4)(−1,3)
The side lengths are 5, 5 and 5√2, and 5² + 5² = (5√2)², so it is a right isosceles triangle.
Q15
The reflection of the point (3, 5) in the x-axis is:
Reflecting in the x-axis changes the sign of the y-coordinate.
Try again ↻