In this item, it is assumed that since the pattern is cut out of the paper which is usually a rectangle then, the shape of the pattern is also rectangle. The perimeter of the rectangle is,
P = 2L + 2W
The area is equal to,
Area = L x W
If we assume that length and width are equal, in order to maximize the space.
1600 cm² = L x L
The value of L from the equation is 40 cm.
2. -28
5. -60
8. -135
The answers are above. :)
There you go!!! Hope I helped :)
Answer:

Step-by-step explanation:
The total surface area of a cone is given by :

Put r = 2r and l = 2l in the above formula

Hence, the total surface area of the cone is
.