Geometry Cabinet Drawers Drawer I Contains six circles varying in diameter from ten to five cm Drawer II Six variations of rectangles: 10x10 cm square, 10x9, 10x8, 10x7, 10x6, 10x5 Drawer III Different types of triangles: equilateral, right-angled isosceles, obtuse-angled isosceles, acute-angled isosceles, right-angled scalene, obtuse angled scalene Drawer IV Different regular polygons: pentagon, hexagon, heptagon, octagon, nonagon, decagon Drawer V Four curvilinear figures: ellipse, quatrefoil, curvilinear triangle, oval Drawer VI Four quadrilaterals: rhombus, right trapezoid, isosceles trapezoid, parallelogram Geometry Cabinet Definitions Circle a closed plane curve consisting of all points at a given distance from a point within it called the center Rectangle a parallelogram having four right angles Square a rectangle having all four sides of equal length Triangle closed plane figure having three sides and three angle Equilateral All sides are of equal length; an equilateral triangle is also equiangular Right-angled Having one right angle (90°) Obtuse-angled Having one angle of greater than 90° Acute-angled Having angle of less than 90° Scalene Having all sides unequal Isosceles Having 2 sides equal Polygon A figure, usually closed-plane, having three or more usually straight sides Pentagon A polygon having 5 angles and 5 sides Hexagon A polygon having 6 angles and 6 sides Heptagon A polygon having 7 angles and 7 sides Octagon A polygon having 8 angles and 8 sides Nonagon A polygon having 9 angles and 9 sides Decagon A polygon having 10 angles and 10 sides Ellipse a plane curve such that the sums of the distances of each point in its periphery from two fixed points, the foci, are equal; (x2/a2) + (y2/b2)=1; if a=b, the ellipse is a circle Oval having the general form, shape or outline of an egg, wider at one end than the other Quatrefoil leaf composed of four leaflets; a panel-like ornament composed of four lobes radiating from a common center Curvilinear triangle triangle consisting of or bound by curved lines Rhombus an oblique-angled equilateral parallelogram (any equilateral parallelogram except a square) Parallelogram quadrilateral having both pairs of opposite sides parallel to each another Trapezoid a quadrilateral plane figure having two parallel and two non-parallel sides Right trapezoid trapezoid with one right angle Isosceles trapezoid trapezoid with two sides of equal length Geometry Cabinet Cards: For each geometric shape in the Montessori geometry cabinet, there are 3 cards on which the shape/inset fits: a solidly filled in one, one with a thick outline and one with a thin outline.