# 1.2: Triangles

- Page ID
- 2632

## Why triangles are important

- All triangles have three sides. (File this fact under the “thank you Captain Obvious” category.)
- All triangles contain 180 degrees.

Figure 9. Triangle

## Different triangles

**Isosceles triangle.** This triangle has two sides that are equal, and two angles that are equal.

Figure 10. Isosceles triangle

**Equilateral triangle.** All three sides of this triangle are equal, and all three of its angles are equal too.

**Similar triangles.** These triangles each have different sized sides, but they share the same sized angles.

## So what about these right triangles you were talking about?

## Ok, so what does a right triangle have to do with electrical?

**vectors** (more on the concept of vectors in a later chapter). These *vectors* each head in a different direction. In fact, they are 90 degrees to each other. When we add them, the sum of these two vectors ends up being the point between the two sides.

**vectorially**. How do you do this? I’m glad you asked.