Use radicals when solving right triangle problems: \( c = \sqrt{a^2 + b^2} \)
A radical is in simplest form when no perfect square factors remain inside the radical
✏️ Worked Examples – Simplifying Radicals to Simplest Form
Perfect Squares to Recognize
A perfect square is the product of a whole number multiplied by itself. Recognizing common perfect squares helps you find factors that can be removed from beneath a square-root symbol.
\(1^2=1\)
\(2^2=4\)
\(3^2=9\)
\(4^2=16\)
\(5^2=25\)
\(6^2=36\)
\(7^2=49\)
\(8^2=64\)
\(9^2=81\)
\(10^2=100\)
Look for the greatest perfect-square factor when possible. This usually simplifies the radical in one step. A smaller perfect-square factor will also work, but you may need to simplify again.
Example 1: Simplify \( \sqrt{45} \)
Find a factor of 45 that is also a perfect square.
\(\sqrt{45}\)
\(\displaystyle =\sqrt{{\color{red}{9}}\times5}\)
The factor \( {\color{red}{9}} \) is a perfect square because \(3^2=9\).
In this lesson, students learn how to simplify square roots by identifying perfect square factors and rewriting expressions in simplest radical form. This skill is important because radicals appear frequently in geometry, especially when using the Pythagorean theorem to find missing side lengths of right triangles. Simplifying radicals helps students express exact answers clearly and prepares them for more advanced algebra and geometry topics.
📚 What You Should Already Know
Students should know how to multiply numbers, recognize perfect squares, and understand the meaning of square roots. They should also be familiar with basic exponent rules, such as \(a^2=a\times a\), and be comfortable factoring numbers.
🚀 What Comes Next
Students will apply simplest radical form when solving right triangle problems using the Pythagorean theorem and when working with irrational numbers. These skills lead directly into distance on the coordinate plane, geometry applications, and algebraic expressions involving radicals.
🧩 Embed This Video in Your LMS
Teachers can embed this YouTube video directly into Canvas, Google Classroom, Schoology, or another learning platform. Click below to show the embed code.
Copy and paste this code into your LMS to embed the video.