Home/ manvi jain/Answers
  1. Asked: In:

    A small terrace at a football ground comprises of 15 steps each of which is 50 m long and built of solid concrete. Each step has a rise of 1/4 m and a tread of 1/2 m. Calculate the total volume of concrete required to build the terrace.

    Best Answer
    manvi jain

    Volume of concrete required to build the first step = 1/4 × 1/2 × 50 = 1/4 × 25 m³ Volume of concrete required to build the second step = 2/4 × 1/2 × 50 = 2/4 × 25 m³ Volume of concrete required to build the third step = 3/4 × 1/2 × 50 = 3/4 × 25 m³ Volume of steps are increasing in AP, whose firstRead more

    Volume of concrete required to build the first step = 1/4 × 1/2 × 50 = 1/4 × 25 m³
    Volume of concrete required to build the second step = 2/4 × 1/2 × 50 = 2/4 × 25 m³
    Volume of concrete required to build the third step = 3/4 × 1/2 × 50 = 3/4 × 25 m³
    Volume of steps are increasing in AP, whose first term a = 1/4 × 25 and the last term
    a₁₅ = 15 /4 × 25. The common difference d = 2/4 × 25 – 1/4 × 25 = 1/4 × 25.
    Therefore, the total volume of concrete required to build the terrace = S₁₅
    = 15/2[(1/4 × 25) + (15 – 1)(1/4 × 25)]
    = 15/2[25/2 + 175] = 15/2 ×200/2 = 750m³
    Hence, the total 750m³ valume of concrete required to build the terrace.

    See less
    • 2
  2. Asked: In:

    Give two different examples of pair of (i) similar figures. (ii) non-similar figures.

    manvi jain
    • 1
  3. Asked: In:

    Prove that a line drawn through the mid-point of one side of a triangle parallel to another side bisects the third side. (Recall that you have proved it in Class IX).

    Best Answer
    manvi jain
    • 1
  4. Asked: In:

    prove that the line joining the mid-points of any two sides of a triangle is parallel to the third side.

    Best Answer
    manvi jain
    • 1
  6. Asked: In:

    ABCD is a trapezium in which AB || DC and its diagonals intersect each other at the point O. Show that AO/BO=CO/DO.

    Best Answer
    manvi jain
    • 1