Question

The height of a square based pyramid having area of its base 81sq. metres is 18 metres . Find the volume of the pyramid.

Ans :486m^2

Answer 1

Given data : The height of a square pyramid whose area is 81 square meters is 18 metres.

To find : Find the volume of the pyramid.

Solution : A/C to given data;

• Area of squared base = 81 m²
• Height of the pyramid, H = 18 m

Now,

Firstly we have to find out, length or side of base of the pyramid. So we use formula of area of square ;

➜ Area of squared base = (side)²

➜ 81 = (side)²

➜ side = √81

➜ side = 9 m ----{1}

A/C to given data,

Here, we know base of the pyramid is square in shape. Hence, from {1} length (L) and breadth (B) of pyramid is 9 m.

Now, to find out, volume of the pyramid, we use formula of volume of pyramid.

➜ Volume of the pyramid = (L * B * H)/3

➜ Volume of the pyramid = (9 * 9 * 18)/3

➜ Volume of the pyramid = (81 * 18)/3

➜ Volume of the pyramid = 1458/3

➜ Volume of the pyramid = 486 m³

Answer : Hence volume of the pyramid is 486 m³.

{More info :

Alternative method : { When area of base and height of the pyramid is given}

➜ Volume of the pyramid = (Area of base * height)/3

➜ Volume of the pyramid = (81 * 18)/3

➜ Volume of the pyramid = 1458/3

➜ Volume of the pyramid = 486 m³}