Noetic Learning
Kinds of Triangles (Online Interactive)
In this triangles learning exercise, students analyze pictures of four triangles. For each triangle, students mark if it is acute, obtuse, or right.
Curated OER
Investigating the Idea of Cos
Fifth graders use cos to solve problems involving right-angled triangles. They solve equations of the form cos(++) = a, for a between -180 and 360 degrees. They state the value of cos(++) in special cases and graph y = cos(++).