We’re surrounded by line segments. These line segments create parallel and perpendicular lines, and acute, obtuse and right angles. Looking for them in our environment is a great way to reinforce them. Ask your kids: Who can find a set of parallel lines? …perpendicular lines? …an acute angle? Pretty soon, they’ll be seeing nothing but lines and angles in the tiles on the floor, the branches of the trees, the way an ice hockey puck hits the wall…

For older kids, get a little more specific: What do you think the angle measurement is on that obtuse angle you just found?

Alignment to the CCSSM:
4.MD.C.5 Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement.
4.MD.C.5a An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles.
4.MD.C.5b An angle that turns through n one-degree angles is said to have an angle measure of n degrees.
4.G.A.1 Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
4.G.A.2 Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.