Let's start with something simple! A right triangle is a special triangle that has one perfectly square corner, just like the corner of a book. This square corner is called a right angle, and it measures exactly ninety degrees.
Now let's learn about the three sides of a right triangle. First, we pick one of the angles that isn't the right angle. The longest side, opposite the right angle, is called the hypotenuse. The side next to our chosen angle is called the adjacent side. And the side across from our chosen angle is called the opposite side.
Now let's learn about SINE! Sine is a special fraction that compares two sides of our triangle. Sine equals the opposite side divided by the hypotenuse. In our example, if the opposite side is 3 and the hypotenuse is 5, then sine equals 3 divided by 5, which equals zero point six.
Now let's learn about COSINE! Cosine is another special fraction that compares two sides of our triangle. Cosine equals the adjacent side divided by the hypotenuse. In our example, if the adjacent side is 4 and the hypotenuse is 5, then cosine equals 4 divided by 5, which equals zero point eight.
To summarize what we've learned: Sine and Cosine are special fractions that help us understand right triangles. Sine equals the opposite side divided by the hypotenuse, while Cosine equals the adjacent side divided by the hypotenuse. These simple ratios help us connect angles and side lengths, making them very useful for solving real-world problems!