Common Core: 8th Grade Math

Explore the foundational concepts of mathematics, including algebra, geometry, and data analysis, essential for 8th-grade students.

Basic Concepts

The Pythagorean Theorem

Right Triangles Revealed

The Pythagorean Theorem is a special rule about right triangles (triangles with a 90-degree angle). It tells us how the lengths of the sides are related. If you know two sides, you can always find the third!

The Magic Formula

The sides that form the right angle are called legs (\( a \) and \( b \)), and the longest side is the hypotenuse (\( c \)). The theorem says:

\[ a^2 + b^2 = c^2 \]

Why is This Important?

This is super useful for measuring distances you can't reach directly. Architects, engineers, and even video game designers use the Pythagorean Theorem to build things and solve problems.

How to Use It

  • Square the lengths of the two legs.
  • Add them together.
  • Take the square root to find the hypotenuse.

Key Formula

\[a^2 + b^2 = c^2\]

Examples

  • A ladder is 10 feet away from a wall and reaches up 24 feet. The length of the ladder is \( \sqrt{10^2 + 24^2} = 26 \) feet.

  • If a rectangular playground is 30 meters long and 40 meters wide, the diagonal across it is \( \sqrt{30^2 + 40^2} = 50 \) meters.

In a Nutshell

The Pythagorean Theorem connects the sides of right triangles to help us measure distances.

Key Terms

Hypotenuse
The longest side of a right triangle, opposite the right angle.
Leg
Either of the two shorter sides of a right triangle that form the right angle.