1. **State the problem:** Isabella has let out 89 feet of string for her kite, which makes an angle of elevation of 40° with the ground. We need to find the height of the kite above the ground. 2. **Identify the formula:** We can model this situation as a right triangle where the string is the hypotenuse ($89$ feet), the height of the kite is the side opposite the angle, and the angle of elevation is $40^\circ$. 3. **Use the sine function:** The sine of an angle in a right triangle is the ratio of the length of the opposite side to the hypotenuse: $$\sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}}$$ Here, $\theta = 40^\circ$, hypotenuse = 89 feet, and opposite = height $h$. 4. **Set up the equation:** $$\sin(40^\circ) = \frac{h}{89}$$ 5. **Solve for $h$:** Multiply both sides by 89: $$h = 89 \times \sin(40^\circ)$$ 6. **Calculate $\sin(40^\circ)$:** Using a calculator, $$\sin(40^\circ) \approx 0.6428$$ 7. **Find $h$:** $$h = 89 \times 0.6428 = 57.1852$$ 8. **Round to the nearest tenth:** $$h \approx 57.2$$ feet **Final answer:** The kite is flying approximately 57.2 feet high.