University of Cambridge
University of Cambridge: Nrich: Four Triangles Puzzle
Sharpen your logic and and pattern recognition skills with this four triangles puzzle. The solution is available to check your work.
Khan Academy
Khan Academy: Quiz: Inscribed Quadrilaterals
Use the fact that opposite angles in an inscribed quadrilateral are supplementary to solve a few problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Inscribed Quadrilaterals in Circles
[Free Registration/Login Required] Students will explore quadrilaterals inscribed in circles with this interactive activity. Click 'Challenge Me' to answer a practice question.
CK-12 Foundation
Ck 12: Geometry: Inscribed Quadrilaterals in Circles
[Free Registration/Login may be required to access all resource tools.] Learn about the Inscribed Quadrilateral Theorem and solve problems involving quadrilaterals inscribed in circles.
Cuemath
Cuemath: Congruent Triangles
Explore the world of congruent triangles in this mini-lesson. Provides a definition and examples that help with understanding their properties. Includes a short video and practice questions with answers.