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- the branch of mathematics that is concerned with the properties and relationships of: - points, lines, angles, curves, surfaces, and solids.
- The visual study of shapes, sizes, patterns, and positions.
What is Geometry?
LineHas no beginning or end.
Continues indefinitely in both directions.
Can be illustrated by drawing arrows at each end.
Line SegmentHas a beginning point and an end
point.
Line segments on a shape are called sides.
Can be found in many shapes.
Made up of two rays with the same start point.
The start point is called the vertex.
The two rays are called the sides of the angle.
Angles
Zero Angles
Right Angles
Acute Angles
Obtuse Angles
Straight Angles
Supplementary Angles
Complimentary Angles
Different Angles
Plane Figure:A two-
dimensional shape (2D).
A shape on a plane. Includes points, lines, polygons, circles, triangles, hexagon, pentagons, etc.
A plane figure is any set of points on a plane.
Familiarize children with different shapes.
Classify and categorize shapes.Observe and listen to gain
insight on the children’s level of reasoning.
Refer to square as a square, and a rectangle is a rectangle.
Counting to 10Should start to examine the
number of sides and angles of some plane figures.
Symbolic A square has 4 sides that are the
same.A triangle has 3 sides.A rectangle has 4 sides.A circle has no sides.
Child’s perception matures and can handle mathematical reasoning.
Explore relationship between size and shape.Most children will claim
that all triangles have the same shape.
Have them explore to see that this concept is not true.
ConcreteHave students compare different
sizes and shapes of triangles, squares, rectangles, and circles.
PictorialHave students take the different shapes
to form another shape.Have students practice making shapes
on a Geoboard.
http://nlvm.usu.edu/en/nav/frames_asid_172_g_2_t_3.html?open=activities
SymbolicSome shapes can be used to form
another shape.Two shapes that are different
sizes can be the same shape.
Size and ShapeChildren need to be well grounded in these concepts
before going on to high school.
Classifying ShapesShould engage in many classifying tasks.build criteria that accurately defines sets of shapes.
A square is a rectangle, a parallelogram, and quadrilateral.
Introduce different terms of shapes.
Concrete (Size & Shape)Have cut outs of different sized shapes.Ask students to show you:
Same shape and size.Same shape, not same size.Same size, not same shape.Different shape, different size.
Pictorial (Size & Shape)Use dot paper or geoboard to illustrate
different size and shapes.
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Quadrilateral - a plane figure having four sides and four angles.
Parallelograms - a quadrilateral having both pairs of opposite sides parallel to each other.
Equilateral Triangle Three equal sides Three equal angles, always 60°
Isosceles Triangle Two equal sides Two equal angles
Scalene Triangle No equal sides No equal angles
Acute Triangle All angles are less than 90°
Right Triangle Has a right angle (90°)
Obtuse Triangle Has an angle more than 90°
Right Isosceles Triangle Has a right angle (90°), and also two equal angles
SymbolicHave all the name of the shapes and
have them come up with a rule for each.Example:
Triangle – has 3 sides.Equilateral Triangle – has 3 equal
sides.
Space figures are three dimensional figures.
Faces: Side of the space figure
Edges: Where two faces meet
Vertex or Vertices: the corners of the space figures
EDGEFACE
VERTEX
Space Figures!
Repeating a shape over and over and over and over and over and over again, leaving no gaps between each shape to form a BIGGER shape.
Another word for “tesselation” is TILING!
Tesselation
Symmetry is having two sides of a whole look like they reflect each other.
Symmetry
Line of Symmetry