1. Perimeter of triangle = 540 cm The ratio of sides of triangle = 12: 17: 25 Let, one of the sides of triangle a = 12 x Therefore, remaining two sides are b = 17 x and c = 25x. We know that the perimeter of triangle = a + b + c ⇒ 540 = 12 x + 17 x + 25 x ⇒ 540 = 54x ⇒ x = 540/54 = 10 So, the sides ofRead more

    Perimeter of triangle = 540 cm
    The ratio of sides of triangle = 12: 17: 25
    Let, one of the sides of triangle a = 12 x
    Therefore, remaining two sides are b = 17 x and c = 25x.
    We know that the perimeter of triangle = a + b + c
    ⇒ 540 = 12 x + 17 x + 25 x
    ⇒ 540 = 54x
    ⇒ x = 540/54 = 10
    So, the sides of triangle are a = 12 × 10 = 120 cm, b = 17 × 10 = 170 cm and c = 25 × 10 = 250 cm.
    So, the semi- perimeter of triangle is given by
    S = (a + b + c /2) = 540/2 = 270 cm
    Therefore, using Heron’s formula, the area of triangle = √s(s – a)(s – b)(s – c)
    = √270(270 – 120)(270 – 170)(270 – 250)
    = √270(150)(100)(20)
    = √81000000
    = 9000 cm²
    Hence, the area of triangle is 9000 cm².

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  2. Perimeter of triangle = 30 cm Two sides of triangle b = 12 cm and c = 12 cm. Let, the third side = a cm We know that the Parimeter of triangle = a + b + c ⇒ 30 = a + 12 + 12 ⇒ 30 - 24 = a ⇒ a = 6 So, the Semi- perimeter of triangle is given by S = a + b + c /2 = 30/2 = 15 cm Therefore, using Heron'sRead more

    Perimeter of triangle = 30 cm
    Two sides of triangle b = 12 cm and c = 12 cm.
    Let, the third side = a cm
    We know that the Parimeter of triangle = a + b + c
    ⇒ 30 = a + 12 + 12
    ⇒ 30 – 24 = a
    ⇒ a = 6
    So, the Semi- perimeter of triangle is given by
    S = a + b + c /2 = 30/2 = 15 cm
    Therefore, using Heron’s formula, the area of triangle = √s(s – a)(s – b)(s – c)
    = √15(15 -6)(15 -12)(15 -12)
    = √15(9)(3)(3)
    = 9√15 cm²
    Hence, the area of triangle is 9√15 cm².

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  3. Radius of capsule r = 3.5/2 = 1.75 mm Volume of medicine to fill the capsule = = 4/3πr³ = 4/3 × 22/7 × 1.75 × 1.75 × 1.75 = 4/3 × 22 × 0.25 × 1.75 × 1.75 = 22.46 mm³ (approx) Hence, 22.46 mm³ medicine is required to fill this capsule.

    Radius of capsule r = 3.5/2 = 1.75 mm
    Volume of medicine to fill the capsule = = 4/3πr³
    = 4/3 × 22/7 × 1.75 × 1.75 × 1.75
    = 4/3 × 22 × 0.25 × 1.75 × 1.75
    = 22.46 mm³ (approx)
    Hence, 22.46 mm³ medicine is required to fill this capsule.

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  4. Surface area of sphere A = 154 cm² Let, the radius of sphere = r cm We know that the surface area of sphere = 4πr² ⇒ 154 = 4 × 22/7 × r² ⇒ r² = (154 × 7)/(22×4) = 49/4 ⇒ r = √49/4 = 7/2 Volume of sphere = 4/2πr³ = 4/3 × 22/7 × (7/2)³ = 4/3 × 22/7 × 7/2 × 7/2 × 7/2 = 539/3 = 179(2/3) cm³ Hence the voRead more

    Surface area of sphere A = 154 cm²
    Let, the radius of sphere = r cm
    We know that the surface area of sphere = 4πr²
    ⇒ 154 = 4 × 22/7 × r²
    ⇒ r² = (154 × 7)/(22×4) = 49/4
    ⇒ r = √49/4 = 7/2
    Volume of sphere = 4/2πr³
    = 4/3 × 22/7 × (7/2)³
    = 4/3 × 22/7 × 7/2 × 7/2 × 7/2
    = 539/3 = 179(2/3) cm³
    Hence the volume of sphere is 179(2/3) cm³.

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  5. Let the internal radius of dome = r m Internal surface area of dome = 2πr² cost of white washing at the rate of Rs 2 = 2πr² × Rs 2 = Rs 4πr² ⇒ Rs 4πr = Rs 498.96 ⇒ 4 × 22/7 × r² = 498.96 ⇒ r² = (498.96×7)/4×22) = 39.69 ⇒ r = √39.69 = 6.3 m Therefore, the internal surface of dome = 2πr² = 2 × 22/7 ×Read more

    Let the internal radius of dome = r m
    Internal surface area of dome = 2πr²
    cost of white washing at the rate of Rs 2 = 2πr² × Rs 2 = Rs 4πr²
    ⇒ Rs 4πr = Rs 498.96
    ⇒ 4 × 22/7 × r² = 498.96
    ⇒ r² = (498.96×7)/4×22) = 39.69
    ⇒ r = √39.69 = 6.3 m
    Therefore, the internal surface of dome = 2πr²
    = 2 × 22/7 × (6.3)2
    = 2 × 22/7 × 6.3 × 6.3
    = 2 × 22 × 0.9 × 6.3
    = 249.98 m²
    Hence, the inside surface area of the dome is 249.48 m².
    (II) Volume of the air inside the dome = 2/3πr³
    = 2/3 × 22/7 × (6.3)³
    = 2/3 × 22/7 × 6.3 × 6.3 × 6.3
    = 2 × 22 × 0.3 × 6.3 × 6.3
    = 523.9 cm³
    Hence, the volume of the air inside the dome is 523.9 cm³.

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