An inequality to model this would be
7x + 8y ≥ 336.
We multiply the number of minutes running, x, by the number of calories burned each minute by running, 7. We multiply the number of minutes swimming, y, by the number of calories burned each minute by swimming, 8. Adding these together, it needs to be greater than or equal to 336, since she wants to burn at least that many calories.
A rectangle has 2 triangle
∴ 25 feet² × 2 = 50 feet²
