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❓ Important Questions

Class 10 Mathematics • Coordinate Geometry • Chapter 7

Exam Focus: These questions cover the most important concepts and applications from Coordinate Geometry.

First solve the question yourself.
Click 🇮🇳 हिंदी में समझें for an easy Hindi explanation.
Click 🇮🇳 हिंदी में Solution देखें to see the complete Hindi solution.

Important Topics: Distance Formula, Section Formula, Midpoint, Trisection, Equidistant Points, Missing Coordinates and Geometrical Applications.

A. Distance Formula

Important Question 1
Distance Between Two Points
Find the distance between the points A(3, 4) and B(7, 1).
हिंदी में समझें: Distance Formula का उपयोग करें:

दोनों points के x-coordinates का difference और y-coordinates का difference निकालकर उनके squares करें। फिर दोनों को जोड़कर square root लें।
Step-by-Step Solution:
Distance AB
A(3,4) B(7,1) x₂ − x₁ y₂ − y₁
The coordinate differences form the two perpendicular sides of a right triangle.
AB = √[(7 − 3)² + (1 − 4)²]
= √(4² + (−3)²)
= √(16 + 9)
= √25
= 5
✅ Final Answer: AB = 5 units
Important Question 2
Distance from the Origin
Find the distance of the point P(6, 8) from the origin.
हिंदी में समझें: Origin के coordinates (0,0) होते हैं। इसलिए P और origin के बीच Distance Formula लगाएँ।
Step-by-Step Solution:
Point P and Origin
O(0,0) P(6,8)
OP = √(6² + 8²)
= √(36 + 64)
= √100
= 10
✅ Final Answer: 10 units
Important Question 3
Missing Coordinate Using Distance
Find the value of y if the distance between A(2, y) and B(2, 7) is 5 units.
हिंदी में समझें: दोनों points का x-coordinate समान है, इसलिए line vertical है। Distance सिर्फ y-coordinates के difference के बराबर होगा।
Step-by-Step Solution:
Vertical Line Segment
B(2,7) A(2,y) 5 units
5 = |7 − y|
Therefore,
7 − y = 5
y = 2
Also, 7 − y = −5 would give y = 12. Therefore two possible points satisfy the given distance.
✅ Final Answer: y = 2 or y = 12
Important Question 4
Equidistant Point
Find the relation between x and y if P(x,y) is equidistant from A(7,1) and B(3,5).
हिंदी में समझें: Equidistant का मतलब है PA = PB. इसलिए दोनों distances के squares बराबर करके equation बनाइए।
Step-by-Step Solution:
PA² = PB²
(x − 7)² + (y − 1)² = (x − 3)² + (y − 5)²

Expanding and simplifying:
−14x − 2y + 50 = −6x − 10y + 34
−8x + 8y + 16 = 0
−x + y + 2 = 0
x − y = 2
✅ Final Answer: x − y = 2

B. Section Formula

Important Question 5
Section Formula
Find the coordinates of the point P which divides the line segment joining A(2,3) and B(8,9) internally in the ratio 2:1.
हिंदी में समझें: Section Formula में ratio m:n दिया गया है। यहाँ m = 2 और n = 1. Formula में B के coordinates को m से और A के coordinates को n से multiply करें।
Step-by-Step Solution:
Internal Division
A(2,3) P B(8,9) 2 1
P = ( 2×8 + 1×2 2+1 , 2×9 + 1×3 2+1 )

= (6,7)
✅ Final Answer: P = (6,7)
Important Question 6
Midpoint Formula
Find the midpoint of the line segment joining A(−4,2) and B(6,8).
हिंदी में समझें: Midpoint में दोनों x-coordinates का average और दोनों y-coordinates का average लेते हैं।
Step-by-Step Solution:
Midpoint M
A(−4,2) M B(6,8) AM = MB
M = ( −4 + 6 2 , 2 + 8 2 )

= (1,5)
✅ Final Answer: M = (1,5)
Important Question 7
Trisection of a Line Segment
Find the coordinates of the two points which trisect the line segment joining A(2,−2) and B(−7,4).
हिंदी में समझें: Trisection का मतलब segment को 3 equal parts में divide करना है। पहला point ratio 1:2 और दूसरा point ratio 2:1 में मिलेगा।
Step-by-Step Solution:
Two Trisection Points
A P Q B
First point P:

P divides AB in ratio 1:2.
P = ( 1(−7) + 2(2) 3 , 1(4) + 2(−2) 3 )

= (−1,0)
Second point Q:

Q divides AB in ratio 2:1.
Q = ( 2(−7) + 1(2) 3 , 2(4) + 1(−2) 3 )

= (−4,2)
✅ Final Answer: P = (−1,0), Q = (−4,2)
Important Question 8
Ratio from a Given Point
Find the ratio in which the point P(5,6) divides the line segment joining A(1,2) and B(7,8).
हिंदी में समझें: मान लें ratio m:n है। Section Formula में P के x और y coordinates के लिए equations बनाकर m:n निकालें।
Step-by-Step Solution:
5 = 7m + n m+n

5m + 5n = 7m + n
4n = 2m
m:n = 2:4 = 1:2
✅ Final Answer: AP : PB = 1 : 2

C. Geometrical Applications

Important Question 9
Isosceles Triangle
Show that the points A(1,2), B(4,6) and C(7,2) form an isosceles triangle.
हिंदी में समझें: तीनों sides की lengths Distance Formula से निकालें। अगर दो sides बराबर मिलती हैं तो triangle isosceles होगा।
Step-by-Step Solution:
Triangle ABC
A(1,2) B(4,6) C(7,2)
AB² = (4−1)² + (6−2)²
= 9 + 16 = 25
AB = 5

BC² = (7−4)² + (2−6)²
= 9 + 16 = 25
BC = 5
Since AB = BC, the triangle is isosceles.
✅ Final Answer: AB = BC = 5 units Therefore ΔABC is isosceles.
Important Question 10
Equilateral Triangle Check
Determine whether the points A(0,0), B(4,0) and C(2,2√3) form an equilateral triangle.
हिंदी में समझें: Equilateral triangle में सभी तीन sides equal होती हैं। इसलिए AB, BC और CA तीनों distances निकालें।
Step-by-Step Solution:
Equilateral Triangle
A(0,0) B(4,0) C(2,2√3)
AB = 4

BC = √[(2−4)² + (2√3−0)²]
= √[4 + 12]
= 4

CA = √[(2−0)² + (2√3−0)²]
= √[4+12]
= 4
✅ Final Answer: AB = BC = CA = 4 units. Therefore ΔABC is equilateral.
Important Question 11
Collinearity Using Distance
Show that the points A(1,2), B(3,4) and C(5,6) are collinear.
हिंदी में समझें: अगर AB + BC = AC हो, तो तीनों points एक ही straight line पर होंगे।
Step-by-Step Solution:
AB = √[(3−1)²+(4−2)²]
= √8

BC = √[(5−3)²+(6−4)²]
= √8

AC = √[(5−1)²+(6−2)²]
= √32
= 2√8
Since AB + BC = √8 + √8 = 2√8 = AC, the three points are collinear.
✅ Final Answer: A, B and C are collinear.
Important Question 12
Rectangle Verification
Show that the points A(1,1), B(6,1), C(6,4) and D(1,4) form a rectangle.
हिंदी में समझें: Opposite sides की lengths compare करें और diagonals की lengths भी check करें।
Step-by-Step Solution:
Quadrilateral ABCD
A B C D
AB = √[(6−1)² + (1−1)²] = 5
BC = √[(6−6)² + (4−1)²] = 3
CD = 5
DA = 3

AC = √[(6−1)² + (4−1)²]
= √34

BD = √[(1−6)² + (4−1)²]
= √34
Opposite sides are equal and both diagonals are equal. Therefore the quadrilateral is a rectangle.
✅ Final Answer: ABCD is a rectangle.
Important Question 13
Find the Ratio
Point P(3,4) divides the line segment joining A(1,2) and B(7,8). Find the ratio AP:PB.
हिंदी में समझें: Section Formula में ratio को m:n मान लें। P के x-coordinate से equation बनाकर ratio निकालें।
Step-by-Step Solution:
3 = 7m + n m+n

3m + 3n = 7m + n
2n = 4m
n = 2m
m:n = 1:2
✅ Final Answer: AP : PB = 1 : 2
Important Question 14
Internal Division with Fractions
Find the coordinates of the point P that divides A(−2,3) and B(4,−5) internally in the ratio 3:2.
हिंदी में समझें: m = 3 और n = 2 लें। Section Formula में numerator और denominator को carefully substitute करें।
Step-by-Step Solution:
P = ( 3(4) + 2(−2) 3+2 , 3(−5) + 2(3) 3+2 )

= ( 12−4 5 , −15+6 5 )

= (8/5, −9/5)
✅ Final Answer: P = (8/5, −9/5)
Important Question 15
Midpoint and Distance
The midpoint of A(2,3) and B(x,y) is (5,7). Find x and y.
हिंदी में समझें: Midpoint Formula में दिए गए midpoint coordinates substitute करें और x तथा y की values निकालें।
Step-by-Step Solution:
5 = 2+x 2
10 = 2+x
x = 8

7 = 3+y 2
14 = 3+y
y = 11
✅ Final Answer: x = 8, y = 11
Important Question 16
Distance Formula Reasoning
Find the value of k if the distance between P(k,3) and Q(4,7) is 5 units.
हिंदी में समझें: Distance Formula लगाकर square both sides करें। फिर quadratic equation solve करें।
Step-by-Step Solution:
5² = (4−k)² + (7−3)²
25 = (4−k)² + 16
(4−k)² = 9
4−k = ±3
k = 1 or 7
✅ Final Answer: k = 1 or k = 7
Important Question 17
Section Formula Application
Find the point dividing the line joining A(−1,4) and B(5,−2) in the ratio 2:3.
हिंदी में समझें: m = 2 और n = 3. B के coordinates को 2 से और A के coordinates को 3 से multiply करें।
Step-by-Step Solution:
P = ( 2(5)+3(−1) 5 , 2(−2)+3(4) 5 )

= (7/5, 8/5)
✅ Final Answer: P = (7/5, 8/5)
Important Question 18
Point Equidistant from Two Points
Find the value of y if the point P(2,y) is equidistant from A(−1,3) and B(5,−3).
हिंदी में समझें: PA = PB लिखकर distance formula के squares equal करें। इससे y की equation मिलेगी।
Step-by-Step Solution:
(2+1)² + (y−3)² = (2−5)² + (y+3)²

9 + y² − 6y + 9 = 9 + y² + 6y + 9
18 − 6y = 18 + 6y
12y = 0
y = 0
✅ Final Answer: y = 0
Important Question 19
Trisection Using Section Formula
Find the coordinates of the point dividing the line segment joining A(−5,7) and B(4,−2) in the ratio 1:2.
हिंदी में समझें: Ratio 1:2 का मतलब point A से ज्यादा पास होगा। Section Formula directly use करें।
Step-by-Step Solution:
P = ( 1(4)+2(−5) 3 , 1(−2)+2(7) 3 )

= (−2,4)
✅ Final Answer: P = (−2,4)
Important Question 20
Coordinate Geometry Board Problem
The points A(−2,3), B(4,5) and C(10,7) are given. Show that B is the midpoint of AC.
हिंदी में समझें: AC का midpoint निकालें। अगर midpoint exactly B(4,5) आता है तो B, AC का midpoint है।
Step-by-Step Solution:
B as Midpoint of AC
A(−2,3) B(4,5) C(10,7) AB = BC
Midpoint of AC = ( −2 + 10 2 , 3 + 7 2 )

= (4,5)
Since the midpoint is B(4,5), B is the midpoint of AC.
✅ Final Answer: B is the midpoint of AC.

⭐ Quick Exam Revision

Before solving a Coordinate Geometry question:

1. Write the coordinates clearly.
2. Identify whether the question asks for distance, midpoint or division in a ratio.
3. Write the formula first.
4. Substitute values carefully.
5. Keep brackets around negative numbers.
6. Simplify the final answer completely.

Most common formulas:

Distance: √[(x₂−x₁)² + (y₂−y₁)²]

Midpoint: x₁+x₂ 2 , y₁+y₂ 2

Section Formula: P = ( mx₂+nx₁ m+n , my₂+ny₁ m+n )