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The image is a page from a math book that deals with solving problems using quadratic equations. Here's a brief overview of the content related to problem 1: **Problem 1:** Find the sides of a right-angled triangle. The hypotenuse is given to be 20 cm, and it’s 4 cm longer than one of the other sides. Use the Pythagorean theorem to find the lengths of the other sides. **Key Steps to Solve:** 1. Let \( x \) be the length of one side; then the other side is \( x + 4 \). 2. Apply the Pythagorean theorem: \[ x^2 + (x + 4)^2 = 20^2 \] 3. Solve the resulting quadratic equation to find \( x \). Once you solve this equation, you'll find the lengths of the two shorter sides.