Can someone help answer the following questions plzz

1)

The area of the pentagon is 8560mmsquared

Change 8560mmsquared top cmsquared

2)

Each side of another pentagon has a length of 101 mm,correct to the nearest millimetre.

(i)Write down the least possible length of each side.

(ii)Write down the greatest possible length of each side

3)Jane's car uses 1 gallon of petrol for every 40 miles. A gallon of petrol costs £3.20

(i) Work out the cost of petrol for Jane's 320 km journey.