Q2 of 35 Page 193

A toy is in the shape of a square pyramid of base edge 16 centimetres and slant height 10 centimetres. What is the total cost of painting 500 such toys, a 80 rupees per square metre?

Given: side of a square = 16cm

Slant Height (l) = 10 cm


We know that,


Surface area of a pyramid


Where, p = perimeter of the base


l = slant height


A = area of the base


Area of a square base (A) = side × side


= 16 × 16


Area of a square base (A) = 256 cm2


Perimeter of a square base (p) = 4 × side


= 4 × 16


Perimeter of a square base (p) = 64 cm


Since, Surface area of a pyramid


⇒ Surface area of a pyramid


Total surface area of pyramid shaped toys = 500 × 576


= 288000cm2


= 28.8m2


Cost of 1m2 = 80Rs.


Cost of 28.8m2 = 28.8 × 80 = 2304 Rs.


More from this chapter

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1

A square of side 5 centimetres, and four isosceles triangles of base 5 centimetres and height 8 centimetres, are to be put together to make a square pyramid. How many square centimeters of paper is needed?

 3

The lateral faces of a square pyramid are equilateral triangles and the length of a base edge is 30 centimetres. What is its surface area?

 4

The perimeter of the base of square pyramid is 40 centimetres and the total length of all its edges is 92 centimetres. Calculate its surface area.

 5

Can we make a square pyramid with the lateral surface area equal to the base area?