Circle Theorems: Triangles in Circles WORKSHEET

This worksheet focuses on exploring triangles within circles and their associated angle properties.

The first section introduces diagrams involving radii, guiding students to calculate missing angles using their knowledge of angles in isosceles triangles. In the second section, the triangles inscribed in the circles are formed using the diameter. Hence, introducing the theorem “the angle in a semicircle at the circumference”.

With its clear focus on foundational concepts, this worksheet serves as an ideal starting point before teaching more of the standard circle theorems, ensuring students gain confidence in working with triangles in circles.

Three-letter angle notation is used throughout.