The Ohio State University at Lima

Irina Boyadzhiev - My GeoGebra Applets



  1. Circumference of a Circle and Pi, April 2015
  2. Trigonometric Functions with Variable Amplitude, Feb. 2015
  3. Graphs of Trigonometric Functions, Feb. 2015
  4. Coterminal and Reference Angles, Feb. 2015
  5. Radians, Number Line and the Unit Circle, Jan. 2015
  6. Visual Proof – a fraction between two given fractions
  7. Golden Triangles and Infinite Series , March 2014
  8. Line Symmetries and the Quadrilaterals Feb. 2014
  9. Midsegmens and Congruent Triangles, Jan. 2014


Some Geometry Problems


Conic Sections

Algebra, Precalculus and Calculus

The Limaçon

Optimization Problems

Bézier Curves

The Equiangular Spiral and Fibonacci Numbers


Number Sense - Fractions

Geometry for K-9 Teachers

Some Simulations

Arc Bound Squarable Shapes