# Getting in Shape

Purpose

This is a level 3 geometry activity from the Figure it Out series.

A PDF of the student activity is included.

Achievement Objectives
GM3-3: Classify plane shapes and prisms by their spatial features.
Student Activity

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Specific Learning Outcomes

Required Resource Materials

FIO, Level 3-4, Geometry, Getting in Shape, page 2

Activity

This activity is designed to reinforce students’ understanding about shape properties of three quadrilaterals – the rectangle, the square, and the rhombus. Students must learn to use the properties to define the shapes. Key words that students should be using with confidence to describe shape properties are: sides, equal, parallel, diagonals, and angles. The students need to study a variety of quadrilaterals so that they can identify properties. The students who don’t understand these properties will have difficulty classifying shapes. For example, they may not understand that a square
is a type of rectangle and that a rectangle is a type of parallelogram. Many activities imply that shapes are distinct and unrelated. The students need to realise that a shape such as a square is also a rectangle, parallelogram, kite, rhombus, and quadrilateral.
To help the students sort quadrilaterals correctly, give them a set of quadrilaterals – squares, rectangles, parallelograms, rhombuses, kites, trapezia, and other quadrilaterals – and get them to sort the shapes according to the following properties:

•  at least one right angle
•  four right angles
•  both pairs of opposite sides equal
• both pairs of opposite angles equal
•  at least one line of symmetry
• more than one line of symmetry
• diagonals equal
•  diagonals that bisect each other.

Alternatively, you could make an enlarged copy of the following flow chart and have the students sort
and name the quadrilaterals using this process.

1a.

b. The only locker that the rectangle can use is the rectangle locker. The only locker that the rhombus can use is the rhombus locker. The square could use any of the
lockers because it is also a rectangle and a rhombus, but two lockers are already
taken, so it has to use the one labelled square locker.
2. a. Rhombus should avoid the diagonal equaliser because it would make him a
square. He should also avoid the rightangled corner shaper because he hasn’t got
any right angles.
b. Rectangle should avoid the side trimmer because it would make him a square.
c. The diagonal equaliser and the side trimmer won’t help Square because his
diagonals and squares are already the same length.
3. a. He could go into any shower because he has equal diagonals, equal angles, and
equal sides.
b. Rectangle could go into the equal diagonals and the equal angles showers.
Rhombus can only go into the equal sides shower.

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