1. Given: AB = 25 cm, AC = 7 cm Let BC be x cm. In right angled triangle ACB, (Hypotenuse)² = (Base)² + (Perpendicular)² [By Pythagoras theorem] ⇒ (AB)² = (AC)² + (BC)² ⇒ (25)² = (7)² ⇒ 625 = 49 + x² ⇒ x² = 625 – 49 = 576 ⇒ x² = √576 = 24 cm Thus, the length of BC is 24 cm. Class 7 Maths Chapter 6 ExerRead more

    Given: AB = 25 cm, AC = 7 cm
    Let BC be x cm.
    In right angled triangle ACB,
    (Hypotenuse)² = (Base)² + (Perpendicular)² [By Pythagoras theorem]
    ⇒ (AB)² = (AC)² + (BC)²
    ⇒ (25)² = (7)²
    ⇒ 625 = 49 + x²
    ⇒ x² = 625 – 49 = 576
    ⇒ x² = √576 = 24 cm
    Thus, the length of BC is 24 cm.

    Class 7 Maths Chapter 6 Exercise 6.5

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-6/

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  2. Given: PQ = 10 cm, PR = 24 cm Let QR be x cm. In right angled triangle QPR, (Hypotenuse)² = (Base)² + (Perpendicular)² [By Pythagoras theorem] ⇒ (QR)² = (PQ)² + (PR)² ⇒ x² = (10)² + (24)² ⇒ x² = 100 + 576 = 676 ⇒ x = √676 = 26 cm Thus, the length of QR is 26 cm. Class 7 Maths Chapter 6 Exercise 6.5Read more

    Given: PQ = 10 cm, PR = 24 cm
    Let QR be x cm.
    In right angled triangle QPR,
    (Hypotenuse)² = (Base)² + (Perpendicular)² [By Pythagoras theorem]
    ⇒ (QR)² = (PQ)² + (PR)²
    ⇒ x² = (10)² + (24)²
    ⇒ x² = 100 + 576 = 676
    ⇒ x = √676 = 26 cm
    Thus, the length of QR is 26 cm.

    Class 7 Maths Chapter 6 Exercise 6.5

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-6/

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  3. Since, the sum of lengths of any two sides in a triangle should be greater than the length of third side. It is given that two sides of triangle are 12 cm and 15 cm. Therefore, the third side should be less than 12 + 15 = 27 cm. And also the third side cannot be less than the difference of the two sRead more

    Since, the sum of lengths of any two sides in a triangle should be greater than the length of third side.
    It is given that two sides of triangle are 12 cm and 15 cm.
    Therefore, the third side should be less than 12 + 15 = 27 cm.
    And also the third side cannot be less than the difference of the two sides.
    Therefore, the third side has to be more than 15 – 12 = 3 cm.
    Hence, the third side could be the length more than 3 cm and less than 27 cm.

    Class 7 Maths Chapter 6 Exercise 6.4

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-6/

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  4. Therefore, In AOB, AB < OA + OB ……….(i) In ∆BOC, BC < OB + OC ……….(ii) In ∆COD, CD < OC + OD ……….(iii) In ∆AOD, DA < OD + OA ……….(iv) Adding equations (i), (ii), (iii) and (iv), we get AB + BC + CD + DA < OA + OB + OB + OC + OC + OD + OD + OA ⇒ AB + BC + CD + DA < 2OA + 2OB + 2OCRead more

    Therefore, In AOB, AB < OA + OB ……….(i)
    In ∆BOC, BC < OB + OC ……….(ii)
    In ∆COD, CD < OC + OD ……….(iii)
    In ∆AOD, DA < OD + OA ……….(iv)
    Adding equations (i), (ii), (iii) and (iv), we get
    AB + BC + CD + DA < OA + OB + OB + OC + OC + OD + OD + OA
    ⇒ AB + BC + CD + DA < 2OA + 2OB + 2OC + 2OD
    ⇒ AB + BC + CD + DA < 2[(AO + OC) + (DO + OB)]
    ⇒ AB + BC + CD + DA < 2(AC + BD)
    Hence, it is proved.

    Class 7 Maths Chapter 6 Exercise 6.4

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-6/

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  5. Since, the sum of lengths of any two sides in a triangle should be greater than the length of third side. Therefore, In ∆ABC, AB + BC > AC ……….(i) In ∆ADC, AD + DC > AC ……….(ii) In ∆DCB, DC + CB > DB ……….(iii) In ∆ADB, AD + AB > DB ……….(iv) Adding equations (i), (ii), (iii) and (iv), weRead more

    Since, the sum of lengths of any two sides in a triangle should be greater than the length
    of third side.
    Therefore, In ∆ABC, AB + BC > AC ……….(i)
    In ∆ADC, AD + DC > AC ……….(ii)
    In ∆DCB, DC + CB > DB ……….(iii)
    In ∆ADB, AD + AB > DB ……….(iv)
    Adding equations (i), (ii), (iii) and (iv), we get
    AB + BC + AD + DC + DC + CB + AD + AB > AC + AC + DB + DB
    ⇒ (AB + AB) + (BC + BC) + (AD + AD) + (DC + DC) > 2AC + 2DB
    ⇒ 2AB + 2BC + 2AD + 2DC > 2(AC + DB)
    ⇒ 2(AB + BC + AD + DC) > 2(AC + DB)
    ⇒ AB + BC + AD + DC > AC + DB
    ⇒ AB + BC + CD + DA > AC + DB
    Hence, it is true.

    Class 7 Maths Chapter 6 Exercise 6.4

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-6/

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