Question: Evaluate the following expression.
$$\left(-\frac{2}{3}\right)^2$$
1. **State the problem:** We need to evaluate the expression $$\left(-\frac{2}{3}\right)^2$$.
2. **Recall the rule:** When squaring a fraction, square both the numerator and the denominator separately.
3. **Apply the formula:**
$$\left(-\frac{2}{3}\right)^2 = \frac{(-2)^2}{3^2}$$
4. **Calculate numerator and denominator:**
$$(-2)^2 = 4$$
$$3^2 = 9$$
5. **Write the simplified fraction:**
$$\frac{4}{9}$$
6. **Final answer:**
$$\boxed{\frac{4}{9}}$$