CK-12 Foundation
Ck 12: Angle Measures
[Free Registration/Login Required] Students explore the concept of finding triangle angle measurement by navigating through the interactive learning module and then answering questions that go along with the module. Students can also...
Illustrative Mathematics
Illustrative Mathematics: 8.g Find the Missing Angle
For this task, 8th graders are presented with a drawing of two parallel lines connected through two line segments. They are given the measures of two angles and are asked to find a third. Aligns with 8.G.A.5.
Illustrative Mathematics
Illustrative Mathematics: 8.g.a Triangle's Interior Angles
In this task, 8th graders are presented with a drawing of two parallel lines with a triangle touching them at all three of its vertices. They are asked to prove that the sum of the triangles' angles equals 180 degrees. Aligns with 8.G.A.5.
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...
National Council of Teachers of Mathematics
Nctm: Illuminations: Angle Sums
Students may use this computer applet to explore angle sums of triangle, quadrilaterals, pentagons and hexagons.
Homeschool Math
Homeschool Math: Equilateral, Isosceles, and Scalene Triangles
This geometry lesson defines equilateral, isosceles, and scalene triangles, and has a variety of exercises, including drawing exercises.