Question

How many triangles will be in the 5th set of triangles?

Answer 1

Answer:

25.

Step-by-step explanation:

I am assuming you only mean the small triangles, not the composite ones.

The  second  triangle set has 3 triangles on bottom row and 1 on the top - total 4.

The 3rd triangle set has 5 triangles on the bottom , 3 on the next up and 1 on the top  - total  9

Following the pattern 4th set will have the number of triaNGLES

7 + 5 + 3 + 1 = 16.

So the 5th will have 9 + 7 + 5 + 3 +1 = 25 triangles.