Interactive
CK-12 Foundation

Proofs: Angle Pairs and Segments—The Three Angle Problem

For Students 9th - 11th
Finding the sum of the measures of three angles is easy, unless you have no clue what the measures are. Learners use an interactive diagram to see a geometric problem in a different way. A set of challenge questions takes them through...
Interactive
Curated OER

Arcs and Chords Multiple Choice

For Students 9th - 10th
In this geometry worksheet, students answer questions about triangles using the correct properties. They find missing angles and sides of triangles. There are 15 questions with an answer key.
Interactive
CK-12 Foundation

Ck 12: Isosceles Triangles

For Students 7th - 9th Standards
[Free Registration/Login Required] Students are given an Isosceles triangle and are asked to move the point on the line segment to explore how the angle measure changes. Click learn more to watch a video demonstration and click challenge...