Trapezoid
Definition
A plane, convex quadrilateral is a trapezoid if, and only if, two of the sides are parallel sides.
Trapezoid elements and classification
Next we will present the Trapezoid Elements and the classification of sides and angles.
PROPERTIES OF TRAPEZOID
Next, we will explore the property of a random trapezoid and two properties of the isosceles trapezoid.
Analysis
What do you notice about the angles and and what about the angles and ? Check the box "Show / Hide lines that pass through A and C and B and D and angles ζ and ε" and prove the argument of this property.
Analysis
What can you notice about the base angles when the trapezoid is an isosceles one? Check the box "Show / Hide Perpendicular Lines to Bases by D and C, Right Angles" and justify the property.