Dear Family,

Your student is learning to classify quadrilaterals by properties such as the number of angles or sides in the quadrilateral. They are organizing quadrilaterals such as kites, rectangles, and rhombuses into a hierarchy. In a hierarchy, all items share the properties of those above them. For example, all quadrilaterals have 4 sides, but only squares have 4 right angles, 4 sides of the same length, and 4 lines of symmetry.

NEW KEY TERMS

kite: A kite is a quadrilateral with at least two pairs of adjacent sides that are the same length. (Lesson 5)

midpoint: The midpoint of a line segment is the point on the line segment that divides it into two line segments of equal length. (Lesson 3)

plane: A plane is a flat, two-dimensional surface that extends forever.(Lesson 1)

property: A property is a characteristic that is true of every item in a category. (Lesson 1)

Familiar Terms

acute angle, acute triangle, attribute, capacity, cube, diagonal, edge, equilateral triangle, face, figure, formula, height, intersect, isosceles triangle, line of symmetry, liquid volume, obtuse angle, obtuse, triangle, parallel, parallelogram, perpendicular, quadrilateral, rectangle, rhombus, right angle, right , triangle, square, square unit, straight angle, supplementary angles, three-dimensional figure, trapezoid, two-dimensional figure, unit square, vertex,

AT HOME ACTIVITY

Quad Search

Walk through your home or neighborhood looking for different types of quadrilaterals. Invite

your student to snap a picture or sketch the shapes you find, and label each by its most

specific name. Discuss where you find each kind of quadrilateral in the hierarchy. “Why do you

think this object is shaped like a rectangle? How would this object look differently if it did not

have 4 right angles?” Consider encouraging your student to use the corner of a book to check

for right angles on the quadrilateral to include it in the correct category.

Hierarchies at Home

Help your student think of ways to classify related objects in your home by using a hierarchy.

Challenge your student to see how many levels of a hierarchy they can create. Remember

that properties need to apply to all the items above each level in the hierarchy. For example,

clothing can be organized into shirts, pants, socks, and hats. Each of these can be organized

by other properties, such as whether the clothing has sleeves, is meant to be worn over or under

other clothing, or is for formal or informal occasions.