I think that she could buy 3 tubes of paint because that's $25.50 and that gives you 28.50 for the canvas.
Area of a circle is

. The first one, a, the radius squared is 8*8=64. So

. If you multiply in pi as 3.14, you'll have 200.96 square inches. The second one, b, the radius squared is 10*10=100. So

square kilometers. If you multiply in pi as 3.14 you'll have 314 square kilometers. The third one, c, the radius squared is 14*14=196. So

. Or you could multiply in pi as 3.14 to get 615.44 yd squared. For the last one, d, the radius squared is 22*22=484 cm. Therefore,

, or multiply in 3.14 for pi to get 1519.76 cm squared. There you go!
2 1/4+1 1/4=3 1/2
or 3.5 (3 and a half yards. )
If you would like to know how many gallons remain to be used, you can do this using the following steps:
lost: 2% of 280 gallons = 2% * 280 gallons = 2/100 * 280 = 5.6 gallons
280 gallons - 5.6 gallons = 274.4 gallons
The correct result would be 274.4 gallons.