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Quiz 4

Develop in a connected way the area formula for rectangles, parallelograms, triangles, and trapezoids. Draw pictures and provide explanations.

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Greedy Triangle

Geometry-NCTM standards Describe, model, draw & classify

shapes; Investigate & predict the results of

combining, subdividing & changing shapes;

Develop spatial sense; Relate geometric ideas to number &

measurement ideas; Recognize and appreciate geometry in

their world.

Geometry

Geometry is the mathematics of the properties and relationships of points, lines, angles, surfaces, and solids.

In geometry, a plane is a 2-dimensional surface that is perfectly flat and infinitely large.

Plane figures are named according to the number, size, and position of their sides and angles. For example, a polygon is a closed figure whose sides are all line segments.

Shape Sort

Polygons

Not Polygons

Polygons

Make a list of all the polygons› Provide one or more pictures for each

A quadrilateral is a polygon that has line segments for each of the four sides. Some quadrilaterals have special traits, so they have special names.

Name of Quadrilateral Description Examples

Trapezoid Exactly one and only one pair of parallel sides

Parallelogram Opposite sides the same length and parallel

Rectangle Parallelogram with 4 right angles

Rhombus Parallelogram with all sides the same length

Square Rectangle with all sides the same length

Solid Figures When we say solid figure, we don’t

mean solid in the usual sense; we mean the figure is not flat, it’s three-dimensional.

face base

edge

vertex

Solid figures include prisms, pyramids, cylinders, cones and spheres. There are several different types of prisms and pyramids, and they are named for their bases.

Tangram Activities:

Make a Tangram Square Use all seven pieces of the

Tangram to make a square with no gaps or overlaps.

Once you have completed your square, cover it up so that the people around you may continue to “enjoy” the challenge.

Tangram Activities:

Grandfather Tang’s Story make Tangram animals.

Composing and decomposing with Tangrams – share Tangram Polygon Challenge

Working with Attributes:

If students discuss kinds of sides, talk about “square angles” or corners and use color tiles to check for them. Have students make Example/Non-example sheets to check for understanding.

Eventually name shapes, use “Shape Sorting Mat” to help with this. Have students make Example/Non-example sheets to check for understanding.

If students discuss parallel sides, use dowel rods to check for them. Use parallel side sort to reinforce this concept. Have students make Example/Non-example sheets to check for understanding.

Common Misconception in Geometry

1. A square is not a rectangle. We teach primary students that there are 4 basic shapes—circles, triangles, rectangles and squares.

And, in math, we have no diamond! It’s either a square or a rhombus.

Draw a square!

Draw a right Triangle

Other problematic issues for students:

Common regular shapes aren't recognized for what they are unless they're upright.