Answer:
16.2 inch²
Step-by-step explanation:
The attached picture consists of 4 equilateral triangles :
Height of equilateral triangle = 2.7 inches
Base of triangle = 3 inches
Area of triangle = 1/2 * base * height
Area of triangle = 1/2 * 3 * 2.7
Area of triangle = 4.05 inch²
Number of square inches of cardboard needed :
Area of each triangle * number of Equilateral triangles
4 * 4.05 inch²
= 16.2 inch²
