Act 1
Which numbered triangle(s) will receive a check mark?
Write down a guess.
Act 2
3. What information would be useful to figure this out?
4. Write down some questions you have in your head right now.
Print the following handout for students to use. Provide a ruler and protractor to give them the opportunity to measure the side lengths and angles of the triangles.
After students have had sufficient time to work with the given tools, consider displaying the following GeoGebra interactive to further explore the triangles.
Act 3
Sequel
5. Create your own sets of triangles and quadrilaterals that receive check marks using the following GeoGebra Interactive.
6. Write down some of your observations from the Sequel interactive. What do you notice? What do you wonder?
Standards
Common Core
HSG.SRT.B.5 - Use congruence and similarity criteria for triangles to solve problems and to prove relationships in geometric figures.
8.G.A.5 - Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.
TEKS
G.7(B) - Apply the Angle-Angle criterion to verify similar triangles and apply the proportionality of the corresponding sides to solve problems
8.3(A) - Generalize that the ratio of corresponding sides of similar shapes are proportional, including a shape and its dilation