Shapes Made of Parts
Part of the Polygons & Quadrilaterals section of Coddy's Geometry journey. Lesson 45 of 59.
Many shapes are not one rectangle but several stuck together. Cut such a shape into pieces you know, find each piece's area, and add them. The rule Area of the parts says the whole has the area of its pieces together.
The dashed cut DG splits this L-shape into two rectangles. The bottom one is 10 by 2, area 20. The top one is 5 by 4, area 20. So the L-shape has area .
On the board, find each piece first with its own rule (tap inside a piece), then tap inside the whole shape and pick Area of the parts.
Challenge
The L-shape ABCDEF is cut by the dashed line DG into two rectangles. Find the area of the whole L-shape, then press Check.
Try it yourself
Find the marked part of the figure
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Polygons & Quadrilaterals
1Polygons
Angles of a QuadrilateralAngles in Any PolygonHow Many Sides?Polygon Angles with xRecap: Polygon Angles4Parallelograms
ParallelogramsNeighbouring AnglesOpposite AnglesParallelograms with xA Diagonal InsideRecap: Parallelograms7On Squared Paper
Make a ParallelogramDraw a Tilted RectangleDraw a RhombusDraw a Trapezoid and KiteRecap: Squared Paper10Composite Shapes
Shapes Made of PartsRectangle and TriangleArea by SubtractingEnough to Find It?Recap: Composite Shapes5Rectangles, 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 Kites