Trapezoids by Area
Part of the Polygons & Quadrilaterals section of Coddy's Geometry journey. Lesson 45 of 61.
On squared paper the trapezoid rule is easy to use: parallel sides along the grid have whole lengths, and the height is the number of rows between them.
This trapezoid has parallel sides 5 and 4 and height 2, so its area is ½ × (5 + 4) × 2 = 9 square units. To build a trapezoid with a given area, choose the height first, then two parallel sides whose sum works out: for area 9 and height 2 the sides must add up to 9.
Challenge
On the squared paper, draw a trapezoid that is not a parallelogram and has area 6. Then press Check.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Polygons & Quadrilaterals
1Polygons
Polygons and DiagonalsAngles of a QuadrilateralAngles in Any PolygonPolygon Angles with xHow Many Sides?Recap: Polygon Angles4Parallelograms
ParallelogramsNeighbouring AnglesOpposite AnglesParallelograms with xA Diagonal InsideRecap: Parallelograms2Regular Polygons
Regular PolygonsFrom an Angle to the SidesInside a Regular PolygonRecap: Regular Polygons5Rectangles, Rhombi, Squares
RectanglesThe Diagonal of a RectangleRhombus AnglesSquaresRecap: Special Parallelograms3Exterior Angles
Exterior AnglesExterior Angles Make 360°Regular Exterior AnglesSides from the ExteriorRecap: Exterior Angles6Trapezoids and Kites
TrapezoidsIsosceles TrapezoidsTrapezoids with xKitesRecap: Trapezoids and Kites9Area of Trapezoids
Area of a TrapezoidA Missing BaseFind the Height FirstTrapezoids by AreaRecap: Trapezoid Area