No, without further information you can't tell which number is greater. This is because there could be any amount of other digits to the right, which changes the value of the leftmost digit depending on the number it is a part of.
Hope this helps! :)
You can work out the perimeter by working out the sum of twice the length (l) and twice the width (w).
2l + 2w = 72
The area is length (l) * width (w)
l * w = 315.
Now we just need to do some rearrangement and isolate one of the terms so we can substitute it back into the area equation.
2l + 2w = 72
2l = 72 - 2w
l = 36 - w
-------
l * w = 315
(36 - w) * w = 315
36w - w² = 315
w² - 36w + 315 = 0
(w - 21)(w + 15) = 0
w = -15 cannot be right, because it can't be negative, so w = 21.
Now that we know the width is 21, we can substitute it into the perimeter equation to work out the length.
2l + 2w = 72
2l + 2(21) = 72
2l + 42 = 72
2l = 72 - 42
2l = 30
l = 15.
Therefore, the width is 21 cm and the length is 15 cm.
12+3=15
19+3=22
15*22=330
You are adding in the frame and then using your area formula of a rectangle.
