[CBSE 2025] In an equilateral triangle of side 10 cm, equilateral triangles of side 1 . . .

In an equilateral triangle of side 10 cm, equilateral triangles of side 1 cm are formed as shown in the figure below, such that there is one triangle in the first row, three triangles in the second row, five triangles in the third row and so on.

Based on the given information, answer the following questions using Arithmetic Progression.

(i) How many triangles will be there in bottom most row? 

(ii) How many triangles will be there in fourth row from the bottom?

(iii) (a) Find the total number of triangles of side 1 cm each till 8th row. 

OR

(b) How many more number of triangles are there from the 5th row to the 10th row than in the first 4 rows? Show working.