Question

Find the area of the cardboard required to pack the square pyramid shaped toy box using nets as shown.

• A. 18 sq ft
• B. 27 sq ft
• C. 36 sq ft
• D. 45 sq ft

Answer 1

The correct option is B 27 sq ft

A square pyramid has 4 triangular faces and a square base as shown in the net.

Here,
Height = 3 ft
Base length(side) = 3 ft

We know,
Area of cardboard required = Area of square + Area of 4 triangles
Area of base (square) = side x side
$=3\times 3$
$=9\text{sq ft}$

$\text{Area of 4 triangles =}4\times \frac{1}{2}\times base\times height$
$=4\times \frac{1}{2}\times 3\times 3$
$=18\text{sq ft}$

Area carboard required = 18 + 9
= 27 sq ft

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ∴ The area of the cardboard required to pack the given pyramid box is 27 sq ft