Illustrative Mathematics
Illustrative Mathematics: 8.g Find the Angle
For this task, 8th graders have to reason with angles and angle measurements, including the sum of the angles in a triangle, to deduce information from a picture. Includes a GeoGebra worksheet that the teacher can use for demonstration...
Khan Academy
Khan Academy: Solve for an Angle in Right Triangles
Given two sides in a right triangle, find one of the acute angles using trigonometry.
OER Commons
Oer Commons: Pre Assessment
Students solve for missing angle measures by applying what they have learned about types of angles and the angle measures of polygons. Students do a pre-assessment at the end of the lesson.