1. Since (2, -1) satisfies both equations, substitute x = 2 and y = -1 into each. For 2mx + 3y = 7, we get 2m(2) + 3(-1) = 7, leading to 4m - 3 = 7, which simplifies to m = 2.5 or 5/2. For 4x + ny = -10, we get 4(2) + n(-1) = -10, simplifying to 8 - n = -10, which gives n = 18.   For more NCERT SoRead more

    Since (2, -1) satisfies both equations, substitute x = 2 and y = -1 into each. For 2mx + 3y = 7, we get 2m(2) + 3(-1) = 7, leading to 4m – 3 = 7, which simplifies to m = 2.5 or 5/2. For 4x + ny = -10, we get 4(2) + n(-1) = -10, simplifying to 8 – n = -10, which gives n = 18.

     

    For more NCERT Solutions of Class 9 Maths Ganita Manjari Part 2 Chapter 13 Two Variables, One Line Question Answer (2026-27)

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  2. i) True: Consecutive interior angles are supplementary, so having one 90° angle forces all angles to equal 90°, forming a rectangle. (ii) False: Diagonals of every rhombus already intersect perpendicularly; it requires equal diagonals or one right angle to become a square. (iii) True: In any paralleRead more

    i) True: Consecutive interior angles are supplementary, so having one 90° angle forces all angles to equal 90°, forming a rectangle.
    (ii) False: Diagonals of every rhombus already intersect perpendicularly; it requires equal diagonals or one right angle to become a square.
    (iii) True: In any parallelogram with equal diagonals, opposite triangles are congruent by SSS, proving the internal angles are right angles.

     

    For more NCERT Solutions of Class 9 Maths Ganita Manjari Part 2 Chapter 12 Quadrilaterals Question Answer (2026-27)

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  3. Let diagonal AC bisect ∠A, so ∠DAC = ∠BAC. By alternate interior angles, ∠BAC = ∠DCA and ∠DAC = ∠BCA. Hence, ∠DCA = ∠BCA, proving AC bisects ∠C. Furthermore, in △ABC, ∠BAC = ∠BCA implies AB = BC. Since adjacent sides of this parallelogram are equal, all four sides are equal, confirming ABCD is a rhoRead more

    Let diagonal AC bisect ∠A, so ∠DAC = ∠BAC. By alternate interior angles, ∠BAC = ∠DCA and ∠DAC = ∠BCA. Hence, ∠DCA = ∠BCA, proving AC bisects ∠C. Furthermore, in △ABC, ∠BAC = ∠BCA implies AB = BC. Since adjacent sides of this parallelogram are equal, all four sides are equal, confirming ABCD is a rhombus.

     

    For more NCERT Solutions of Class 9 Maths Ganita Manjari Part 2 Chapter 12 Quadrilaterals Question Answer (2026-27)

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  4. (i) Yes: Diagonals bisecting vertex angles force all opposite sides parallel and adjacent sides equal, creating a rhombus. (ii) Yes: Perpendicular bisecting diagonals prove all four sides are congruent through SAS triangle congruences. (iii) No: Non-rectangular shapes like isosceles trapeziums haveRead more

    (i) Yes: Diagonals bisecting vertex angles force all opposite sides parallel and adjacent sides equal, creating a rhombus.
    (ii) Yes: Perpendicular bisecting diagonals prove all four sides are congruent through SAS triangle congruences.
    (iii) No: Non-rectangular shapes like isosceles trapeziums have equal diagonals. Extra condition: Add that the diagonals must bisect each other or the quadrilateral must already be a parallelogram.

     

    For more NCERT Solutions of Class 9 Maths Ganita Manjari Part 2 Chapter 12 Quadrilaterals Question Answer (2026-27)

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  5. Adjacent angles of parallelogram ABCD are supplementary, summing to 180°. In triangles formed by adjacent bisectors, half-angles sum to 90°, forcing each intersection angle to be 90°. As all four interior angles equal 90°, the figure PQRS is a rectangle. We assume AB ≠ BC because if AB = BC (a rhombRead more

    Adjacent angles of parallelogram ABCD are supplementary, summing to 180°. In triangles formed by adjacent bisectors, half-angles sum to 90°, forcing each intersection angle to be 90°. As all four interior angles equal 90°, the figure PQRS is a rectangle. We assume AB ≠ BC because if AB = BC (a rhombus), the angle bisectors are the diagonals, which concur at one point rather than forming a quadrilateral.

     

    For more NCERT Solutions of Class 9 Maths Ganita Manjari Part 2 Chapter 12 Quadrilaterals Question Answer (2026-27)

    https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-12/

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