Defining a Trapezoid
A trapezoid is a flat, four-sided shape (a quadrilateral) that is defined by having at least one pair of parallel sides. These parallel sides are known as the bases of the trapezoid, and the other two, non-parallel sides are called the legs.
Section 2: Key Properties
The defining property of a trapezoid is its single pair of parallel bases. The angles on the same leg (the angles between a base and a leg) are supplementary, which means they add up to 180 degrees. The lengths of the sides and the measures of the angles can vary, which leads to different classifications of trapezoids.
Section 3: A Practical Example
A common example of a trapezoid is the shape of a typical bucket or a lampshade when viewed from the side. The top and bottom openings represent the two parallel bases of different lengths, and the slanted sides represent the legs. Many bags, architectural features, and even some slices of pizza can also have a trapezoidal shape.
Section 4: Types of Trapezoids
There are special types of trapezoids. An isosceles trapezoid has legs of equal length and its base angles are equal. A right trapezoid has at least two right angles (90°). A parallelogram is also a special case of a trapezoid because it has two pairs of parallel sides, satisfying the 'at least one pair' rule.