Output:

Please enter the length of your kite.
134
Please enter the width of your kite.
45
So the length is 134cm and the width is 45cm.
The area of your kite is 0.3015 square meters.
Your kite weighs 0.398885 kg.

Alternative Output:

Please enter the length of your kite.
450
Please enter a length between 1 and 400.
Please enter the length of your kite.
350
Please enter the width of your kite.
0
Please enter a width between 1 and 400.
Please enter the width of your kite.
350
So the length is 350cm and the width is 350cm.
The area of your kite is 6.125 square meters.
NOTE: A lower aspect ratio (below 1) would provide more stability
Your kite weighs 8.10337 kg.