Sides Right Triangle
1. **State the problem:** We have a right triangle where the altitude is 7 cm less than the base, and the hypotenuse is 13 cm. We need to find the lengths of the other two sides (base and altitude).
2. **Define variables:** Let the base be $x$ cm. Then the altitude is $x - 7$ cm.
3. **Apply the Pythagorean theorem:** For a right triangle with legs $a$, $b$ and hypotenuse $c$, we have:
$$a^2 + b^2 = c^2$$
Here, $a = x$, $b = x - 7$, and $c = 13$.
So,
$$x^2 + (x - 7)^2 = 13^2$$
4. **Expand and simplify:**
$$x^2 + (x^2 - 14x + 49) = 169$$
$$2x^2 - 14x + 49 = 169$$
5. **Bring all terms to one side:**
$$2x^2 - 14x + 49 - 169 = 0$$
$$2x^2 - 14x - 120 = 0$$
6. **Simplify by dividing all terms by 2:**
$$x^2 - 7x - 60 = 0$$
7. **Factor the quadratic:**
$$x^2 - 7x - 60 = (x - 12)(x + 5) = 0$$
8. **Solve for $x$:**
$$x - 12 = 0 \Rightarrow x = 12$$
$$x + 5 = 0 \Rightarrow x = -5$$ (not possible since length cannot be negative)
9. **Find the altitude:**
$$x - 7 = 12 - 7 = 5$$
10. **Final answer:** The base is 12 cm and the altitude is 5 cm.