**LESSON 5. Variable
Based Triangle**
Let’s investigate a
basic design. A simplest **polygon** is a **triangle**, composing of
only three sides and three angles. The triangle is structural a rigid and
sturdy shape. In simple machine terms it would be a wedge. If you look
around you see many structures that use a triangle as a base. Even, if you
look at the roof of many structures you can immediately see the triangle.
You
can classify triangles by **sides** and by **angles.** There are three
basic shapes by sides including **equilateral, isosceles, **and **
scalene. **An **equilateral **triangle has
three equal sides. In this
type of triangle, the angles are all equal (equiangular). An **isosceles**
triangle has just two equal sides. The third side is called the **base**
and the two equal sides are called **legs.** Triangles with three sides of
different lengths are called a **scalene** triangle. |