Triangle Dimensions
1. **State the problem:** We need to find the base and height of a triangle where the base is 4 cm less than twice its height, and the area is 60 cm².
2. **Define variables:** Let the height be $h$ cm.
3. **Express the base in terms of height:** The base $b = 2h - 4$ cm.
4. **Use the area formula for a triangle:** Area $= \frac{1}{2} \times \text{base} \times \text{height}$.
5. **Set up the equation:**
$$60 = \frac{1}{2} \times (2h - 4) \times h$$
6. **Simplify the equation:**
$$60 = \frac{1}{2} (2h^2 - 4h) = h^2 - 2h$$
7. **Rewrite as a quadratic equation:**
$$h^2 - 2h - 60 = 0$$
8. **Solve the quadratic equation:**
Using the quadratic formula $h = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$ where $a=1$, $b=-2$, $c=-60$:
$$h = \frac{2 \pm \sqrt{(-2)^2 - 4 \times 1 \times (-60)}}{2} = \frac{2 \pm \sqrt{4 + 240}}{2} = \frac{2 \pm \sqrt{244}}{2}$$
9. **Calculate the square root:**
$$\sqrt{244} = \sqrt{4 \times 61} = 2\sqrt{61}$$
10. **Find the two possible values for $h$:**
$$h = \frac{2 \pm 2\sqrt{61}}{2} = 1 \pm \sqrt{61}$$
11. **Choose the positive value for height:**
$$h = 1 + \sqrt{61} \approx 1 + 7.81 = 8.81 \text{ cm}$$
12. **Find the base:**
$$b = 2h - 4 = 2(8.81) - 4 = 17.62 - 4 = 13.62 \text{ cm}$$
**Final answer:**
The height is approximately $8.81$ cm and the base is approximately $13.62$ cm.