Tin-Foil Twinkles

Be a geometry detective! Cut out and design these shiny 3-dimensional stars. They’re filled with angles.

• 1.

  Talk about ways to describe shapes using words such as sides, corners, lines, and angles. Analyze familiar 2-dimensional plane figures, such as squares, triangles, and rectangles. Identify properties that make each shape unique. Compare familiar 3-dimensional space figures such as cubes and pyramids. What properties make these shapes unique?

• 2.

  Here’s a new way to create paper stars that are unique. Fold an 8-inch (10 cm) square piece of construction paper in half to form a rectangle. Hold the rectangle so the fold is at the bottom. Bring up the bottom right point to meet the left side about 1/3 of the way down from the top left corner. Press down on fold.

• 3.

  Fold the lower left triangle piece up over the top. Press down on fold.

• 4.

  Fold the right half of the shape (from the folded triangle to the right tip) over to the left. Your folded paper resembles an ice cream cone with 2 scoops of pointy ice cream, one large and one small!

• 5.

  Use Crayola® Scissors to cut the folded paper from about 1/3 of the way from the bottom of the right fold to the corner of the angle on the left side. Discard the "ice cream scoops."

• 6.

  Open the folded paper "cone" to reveal your star. Crease all the fold lines that end in a point so they are folded up. Crease all the in-between fold lines so they fold down. Make several stars. Experiment with other paper sizes.

• 7.

  Cut pieces of colored art foil to fit on some of the star surfaces. Attach foil with a Crayola Glue Stick.

• 8.

  Use Crayola Gel Markers and your imagination to draw designs on the foil and paper surfaces of your stars.

• 9.

  Compare your stars with your classmates’ stars. Each star may have a unique shape. Analyze the surfaces. Are all surfaces around the same star the same plane figure? Describe and measure sides (lines) and corners (angles). Are some angles larger and other

• 10.

  After you have explored your stars, use them to decorate a bulletin board for science and math or for holiday gifts.

Benefits

• Students compare and discuss characteristics and properties of 2- and 3-dimensional shapes.
• Students construct 3-dimensional paper star figures, imaginatively customizing them with art tools and craft materials.
• Students analyze their 3-dimensional star shapes using geometry vocabulary.

Adaptations

• Vary the cutting steps to see how your resulting star figures change. Use this bank of star shapes to classify and compare them based on their geometric properties.
• Turn Tin-Foil Twinkles into a study of fractions. What fraction of your star is covered with foil? Use fractions to plan each star’s foil and marker designs. Compare stars, discussing designs using fraction descriptions.
• Incorporate this geometry experience with studies of space and stars, celebration of holidays, and elementary and advanced geometry and trigonometry lessons.
• Construct 50 stars for a U.S. flag display, giving each star a unique design dedicated to one state. What other countries have stars on their flags? Make replicas of those flags.