.1125 = 11.25% or 11 1/4(fraction)
Refer to the attached image. Since one vertex is the origin and the other two lay on the coordinate axes, the triangle is a right triangle. This means that, if we consider AB to the be base, AC is his height, and vice versa.
Anyway, it means that the area is given by

Since AB is a horizontal segment and AC is a vertical segment, their length is given by the absolute difference of the non-constant coordinate: points A and B share the same x coordinate, so we subtract the y coordinates:

The opposite goes for AC: points A and C share the same y coordinate, so we subtract the x coordinates:

So, the area is

Answer:
He can buy 2 outfits
Step-by-step explanation:
How to arrive at the answer is: Since it says that Mr. Trager bought a new bike for $273.98. Subtract $ 273.98 from $ 500.00. The answer is $ 226.02. Then it says he bought 3 bike reflectors for $ 7.23.To find how much the bike reflectors cost, multiply 7.23 by 3. The answer is $21.69. Then subtract $ 21.69 from $ 226.02. The answer is $ 204.33. Then it says he bought a helmet for $ 42.36. Subtract $ 42.36 from $ 204.33. The answer is $ 161.97. Then it says he plans to buy cycling outfits for $ 78.12 each. To find out how many he can buy, subtract $ 78.12 until you can't anymore. You can subtract $ 78.12 once and the answer is $ 83.85. It looks like we can subtract one more time. Then we subtract $ 78.12 again, and he has $ 5.73 left. We subtracted twice, so he can buy 2 outfits.