Question

Find the number of triangles in the given figure:

• A. 16
• B. 13
• C. 12
• D. 15
• E. 14

Hint:

Use a pencil to trace or a system of labeling points (like A, B, (c) to ensure you count every unique triangle only once.

Answer 1

Answer: (E)

Step 1: Systematic Counting:
Count the smallest triangles first. Then, count triangles formed by combining two or more small triangles. Label the vertices to help with identification.
Step 2: Categorize by Size:
Group triangles by size (e.g., 1-unit, 2-unit, 3-unit) and count each group separately to avoid missing any.
Step 3: Final Answer:
Sum the counts from all categories to get the total number of triangles.