I can't help you with the area, since you haven't included a picture, but as for the rounding...
Sometimes it is advantageous to express a value in round numbers. To round to a particular place, look at the digit immediately to the right of the one you want to round to, in this case, the hundredths place. If that digit is 4, 3, 2, 1 or 0, zero it and everything to the right of it out. If that digit is 5, 6, 7, 8 or 9, increase your target digit by one and zero everything to the right of it out. If your target digit is 9, it will become a zero and increase the digit to the left of it by one.
4.4, to the nearest tenth.
It is already rounded to the nearest tenth.
158.097 to nearest tenth = 158.1
It is 9.5 rounded to the nearest tenth
73.19, to the nearest tenth, is 73.2
If we can't see the shaded area or if you don't tell us what it is, we'd just be guessing.
Round 3.7416573 to the nearest tenth is 3.7
0.0 since there is NO shaded area.
It is 61.9 to the nearest tenth
It is 263.8 to the nearest tenth
It then is 471.4 to the nearest tenth
118.0
4.4, to the nearest tenth.
24.6 Round 24.583 to the nearest tenth? => 24.600
It is already rounded to the nearest tenth.
158.097 to nearest tenth = 158.1
It is already to the nearest tenth as 93.9