Question

number of triangles 2 3 ? ? perimeter (units) 4 5 ? ?

Explanation:

Step1: Analyze the pattern of triangles

Looking at the first two figures, the number of triangles is 2, 3. So the pattern is increasing by 1 each time. Thus, the next two numbers of triangles are \(3 + 1=4\) and \(4 + 1 = 5\).

Step2: Analyze the pattern of perimeter

For the first figure (2 triangles), perimeter is 4. For the second figure (3 triangles), perimeter is 5. The pattern here is that for each additional triangle, the perimeter increases by 1. So for 4 triangles, perimeter is \(5+1 = 6\); for 5 triangles, perimeter is \(6 + 1=7\).

Answer:

For the number of triangles: 4, 5; For the perimeter: 6, 7