Home
Class 10
MATHS
The points A (-1,-2), B (4,3) ,C (2,5) a...

The points A (-1,-2), B (4,3) ,C (2,5) and D (-3,0) in that order form a rectangle.

Text Solution

AI Generated Solution

The correct Answer is:
To prove that the points A (-1,-2), B (4,3), C (2,5), and D (-3,0) form a rectangle, we need to show two things: 1. The quadrilateral formed by these points is a parallelogram. 2. The angles between adjacent sides are 90 degrees. ### Step 1: Prove that the quadrilateral is a parallelogram A quadrilateral is a parallelogram if the midpoints of its diagonals are the same. We will find the midpoints of diagonals AC and BD. **Finding the midpoint of AC:** - A = (-1, -2) - C = (2, 5) Midpoint of AC = \(\left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right)\) = \(\left(\frac{-1 + 2}{2}, \frac{-2 + 5}{2}\right)\) = \(\left(\frac{1}{2}, \frac{3}{2}\right)\) **Finding the midpoint of BD:** - B = (4, 3) - D = (-3, 0) Midpoint of BD = \(\left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right)\) = \(\left(\frac{4 - 3}{2}, \frac{3 + 0}{2}\right)\) = \(\left(\frac{1}{2}, \frac{3}{2}\right)\) Since the midpoints of AC and BD are the same, we conclude that the quadrilateral ABCD is a parallelogram. ### Step 2: Prove that the angles between adjacent sides are 90 degrees To show that the angle between adjacent sides is 90 degrees, we can use the distance formula to find the lengths of the sides and then apply the Pythagorean theorem. **Finding the lengths of the sides:** 1. **Length of DC:** - D = (-3, 0) - C = (2, 5) Using the distance formula: \[ DC = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} = \sqrt{(2 - (-3))^2 + (5 - 0)^2} = \sqrt{(2 + 3)^2 + 5^2} = \sqrt{5^2 + 5^2} = \sqrt{50} \] 2. **Length of BC:** - B = (4, 3) - C = (2, 5) Using the distance formula: \[ BC = \sqrt{(2 - 4)^2 + (5 - 3)^2} = \sqrt{(-2)^2 + 2^2} = \sqrt{4 + 4} = \sqrt{8} \] 3. **Length of BD:** - B = (4, 3) - D = (-3, 0) Using the distance formula: \[ BD = \sqrt{(-3 - 4)^2 + (0 - 3)^2} = \sqrt{(-7)^2 + (-3)^2} = \sqrt{49 + 9} = \sqrt{58} \] ### Step 3: Verify using Pythagorean theorem According to the Pythagorean theorem, if ABCD is a rectangle, then: \[ DC^2 + BC^2 = BD^2 \] Calculating: - \(DC^2 = 50\) - \(BC^2 = 8\) - \(BD^2 = 58\) Now check: \[ 50 + 8 = 58 \] Since this holds true, we conclude that angle C is 90 degrees. ### Conclusion Since we have shown that ABCD is a parallelogram and that the angles between adjacent sides are 90 degrees, we can conclude that the points A (-1,-2), B (4,3), C (2,5), and D (-3,0) form a rectangle. ---

To prove that the points A (-1,-2), B (4,3), C (2,5), and D (-3,0) form a rectangle, we need to show two things: 1. The quadrilateral formed by these points is a parallelogram. 2. The angles between adjacent sides are 90 degrees. ### Step 1: Prove that the quadrilateral is a parallelogram A quadrilateral is a parallelogram if the midpoints of its diagonals are the same. We will find the midpoints of diagonals AC and BD. ...
Promotional Banner

Topper's Solved these Questions

  • COORDINATE GEOMETRY

    NCERT EXEMPLAR ENGLISH|Exercise Exercise 7.3 Very Short Answer Type Questions|20 Videos
  • COORDINATE GEOMETRY

    NCERT EXEMPLAR ENGLISH|Exercise Exercise 7.4 Long Answer Type Questions|6 Videos
  • COORDINATE GEOMETRY

    NCERT EXEMPLAR ENGLISH|Exercise Exercise 7.4 Long Answer Type Questions|6 Videos
  • CONSTRUCTIONS

    NCERT EXEMPLAR ENGLISH|Exercise Exercise 10.4 Long Answer type Questions|7 Videos
  • INTRODUCTION TO TRIGoNOMETRY AND ITS APPLICATIONS

    NCERT EXEMPLAR ENGLISH|Exercise LONG ANSWER TYPES QUESTIONS|18 Videos

Similar Questions

Explore conceptually related problems

Plot the points A(4,2),B(-5,3),C(-4,-5) and D(5,-2) .

Prove that the points (-4, -1), (-2, -4), (4,0) and (2,3) are the vertices of a rectangle.

Show that the points A (1, 0), B(5, 3), C (2, 7) and D(-2, 4) are the vertices of a rhombus.

Prove that the points A(4,3),B(6,4),C(5,-6)a n d D(-3,5) in that order are the vertices of a parallelogram.

The points (5,-4,2), (4,-3,1), (7,6,4) and (8,-7,5) are the vertices of a. a rectangle b. a square c. a parallelogram d. none of these

Show that the points A(2,3,5),B(-4,7,-7),C(-2,1,-10) and D(4,-3,2) are the vertices of a rectangle.

Using slopes, prove that the points A(-2,-1) , B(1,0) , C(4,3) and D(1,2) are the vertices of a parallelogram.

Prove that the points (3,\ 0),\ (4,\ 5),\ (-1,\ 4) and (-2,\ -1) , taken in order, form a rhombus. Also, find its area.

Show that the points A(2, 1), B(0,3), C(-2, 1) and D(0, -1) are the vertices of a square.

Prove that the point A(1,3,0),\ B(-5,5,2),\ C(-9,-1,2)\ a n d\ D(-3,-3,0) taken in order are the vertices of a parallelogram. Also, show that ABCD is not a rectangle.