Quick Line and Rotational Symmetry Project

Quick Line and Rotational Symmetry Project

A quick project to introduce symmetry: You can either provide or have them use a protractor to draw some simple geometric shapes on construction paper.  I typically require a square, an equilateral triangle, and a third polygon of their choice. 

Popsicle Stick Snowflakes: A Holiday Craft

Popsicle Stick Snowflakes: A Holiday Craft

I saw this Popsicle stick snowflake craft on Pinterest and immediately fell in love!  My preschooler loves Popsicle stick crafts, and he has been itching to get ready for Christmas, so this was a perfect fit for a recent Saturday

Area of Mixed Polygons

Area of Mixed Polygons

In 7th grade math, we’re working on area.  We’ve gone through all of the basic formulas with careful attention to how they are related to one another — the triangle being half of a rectangle, the trapezoid being a combination

Units vs. Square Units (vs. Cubic Units)

When teaching basic geometry concepts, such as perimeter and area, you will save yourself quite a bit of grief if you start by making clear the difference between units and square units. Our common abbreviations for these, such as cm

Pythagorean Theorem Follow-Up

Pythagorean Theorem Follow-Up

Activity for the big kids today: Without using a ruler, determine whether this triangle is equilateral, isosceles, or scalene. Prove it.

Pythagorean Theorem

Pythagorean Theorem

In over our heads with radicals in 8th grade Algebra this week, so we took some time to review the Pythagorean Theorem.  Geometry is so beautifully concrete.  In addition to demonstrations you can do with drawings and such, here’s an

Geometry in the Real World

Geometry in the Real World

Whenever I’m working on geometry with my students, I try to keep the focus as real-world as possible.  So much of math operates in the abstract; geometry, by contrast, is thoroughly tangible.  This is a time when we can easily

Geometry Across the Curriculum

Geometry Across the Curriculum

I use geometric drawing across the curriculum in several projects.  Below is an in-progress shot of an 8th-grader’s design for a stained glass window, an assignment from my medieval history unit that incorporates symbolism along with geometric design. In world

Construct a Hexagon

Construct a Hexagon

The construction for a regular hexagon is a favorite of my students every year and the one most of them choose as a basis for their geometric design project.  We are simply going to begin with a line and use

Bisect an Angle

Bisect an Angle

Today we’ll be bisecting an angle, i.e. cutting an angle in half without using a protractor to measure.  Begin with any angle and draw an arc from the vertex (V) such that your arc crosses both rays of the angle.