GCSE›Edexcel GCSE Maths›Mind mapsProperties of 2D ShapesEdexcel GCSE Maths: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsVocabularyVertices are corners, edges are sidesParallel lines never meetPerpendicular lines meet at 90°A polygon is a closed shape with straight sidesRegular: all sides and angles equalQuadrilateralsSquare: 4 equal sides, 4 right anglesRectangle: opposite sides equal, 4 right anglesParallelogram: opposite sides equal and parallelTrapezium: exactly one pair of parallel sidesKite: two pairs of adjacent equal sidesRhombus: 4 equal sides, opposite sides parallelSymmetryLine of symmetry: folds onto itself exactlyRotational order: matches in one full turnSquare: 4 lines, order 4Equilateral triangle: 3 lines, order 32D shapesproperties and angles180°360°Angle sumsTriangle angles add to 180°Polygon interior sum =(n−2)×180°= (n-2) \times 180°=(n−2)×180°Regular interior angle =(n−2)×180°n= \frac{(n-2) \times 180°}{n}=n(n−2)×180°Regular exterior angle =360°n= \frac{360°}{n}=n360°Interior + exterior = 180°Worked exampleRegular hexagon, n=6n = 6n=6Sum =4×180°=720°= 4 \times 180° = 720°=4×180°=720°Interior angle =120°= 120°=120°Exterior angle =60°= 60°=60°Exam tipsA square is also a special rectangle and rhombusLearn each shape's properties to find missing anglesUse exact vocabulary when explaining