Geometric Visualization of the Arithmetic Progression Formula

This GeoGebra example demonstrates how the general term of an arithmetic progression is derived and visualized using the first term and common difference. It highlights the step-by-step algebra leading to the relationship an = a + (n − 1)d and supports understanding of the linear growth pattern in the sequence. Key concepts include arithmetic progression, parameters a (first term), d (common difference), n (term index/count), and the general term formula an. Construction-wise, the setup uses the variables/objects a, n, d, along with additional objects A, B, C for the visual context, and text objects (text1, text2) to display the chained equalities that expand and simplify an = a + (n − 1)d into successive equivalent forms. The activity is suitable for middle school through early undergraduate students, especially for teaching and interactive practice of sequence formulas and their derivations.