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Flat Shapes and Polygons
Names and properties of 2D shapes, polygons by number of sides, and kinds of triangles and quadrilaterals.
0 of 49 known
49 cards
- TriangleShape3 sides, 3 angles
- QuadrilateralShape4 sides, 4 angles
- PentagonShape5 sides
- HexagonShape6 sides
- HeptagonShape7 sidesAlso called a septagon
- OctagonShape8 sidesA stop sign
- NonagonShape9 sides
- DecagonShape10 sides
- HendecagonShape11 sidesAlso called an undecagon
- DodecagonShape12 sides
- CircleShapeAll points the same distance from the center; no sides or corners
- Oval (ellipse)ShapeA stretched circle
- SquareShape4 equal sides and 4 right angles
- RectangleShape4 right angles; opposite sides equal
- RhombusShape4 equal sides; opposite angles equal
- ParallelogramShapeBoth pairs of opposite sides are parallel and equal
- TrapezoidShapeA quadrilateral with at least one pair of parallel sides
- KiteShapeA quadrilateral with two pairs of equal sides that meet side by side
- Equilateral triangleShapeAll 3 sides equal; all angles 60 degrees
- Isosceles triangleShapeAt least 2 equal sides and 2 equal angles
- Scalene triangleShapeNo equal sides
- Right triangleShapeHas one 90-degree angle
- Acute triangleShapeAll three angles are less than 90 degrees
- Obtuse triangleShapeHas one angle greater than 90 degrees
- Regular polygonShapeA polygon with all sides equal and all angles equal
- Irregular polygonShapeA polygon whose sides or angles are not all equal
- Convex polygonShapeA polygon with no angle pointing inward
- Concave polygonShapeA polygon with at least one angle pointing inward
- Sum of angles in a triangleShape180 degrees
- Sum of angles in a quadrilateralShape360 degrees
- Sum of angles in a pentagonShape540 degrees
- Sum of angles in a hexagonShape720 degrees
- Sum of angles in an n-sided polygonShape(n − 2) × 180 degrees
- Each angle of a regular hexagonShape120 degrees
- Each angle of a regular pentagonShape108 degrees
- Each angle of a regular octagonShape135 degrees
- Number of diagonals of a quadrilateralShape2
- Number of diagonals of a pentagonShape5
- Number of diagonals of a hexagonShape9
- DiagonalShapeA segment joining two corners of a polygon that are not next to each other
- Is a square a rectangle?ShapeYes. A square is a rectangle with all sides equal.
- Is a square a rhombus?ShapeYes. A square is a rhombus with right angles.
- Is a rectangle a parallelogram?ShapeYes. Its opposite sides are parallel.
- Do the diagonals of a rectangle have equal lengths?ShapeYes
- Do the diagonals of a rhombus meet at right angles?ShapeYes, and they bisect each other
- CrescentShapeA moon shape formed by two arcs
- SemicircleShapeHalf of a circle
- Quarter circleShapeA quarter of a circle; a 90-degree sector
- Star shape (pentagram)ShapeA five-pointed star drawn with five straight lines
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