## Tags » Arithmetic Progression

#### Sets of 3 square numbers in arithmetic progression

SUMMARY

(1) Find more solutions

(2) Find a triangle (a, b, c) where (a, b, c) are integers and are in arithmetic progression (AP)

Are cot A, cot B and cot C always in AP? 32 more words

#### 3 Triangular numbers in arithmetic progression

**Can you find another set of 3 Triangular numbers in arithmetic progression whose common difference is triangular?**

Paul found:

in two ways:

**For n = 5, can you find sets of 3 Pentagonal numbers in AP whose common difference is pentagonal?** 64 more words