यदि 5 शीर्षों वाला एक नियमित तारा बहुभुज (पंचकोण तारा) बनाया जाता है, तो उसके अंदर कुल कितने त्रिभुज बनते हैं?

How many triangles are present in a figure where a main triangle is divided by two straight lines drawn from its top vertex to the base, and intersected by three horizontal lines parallel to the base?

How many total triangles are there in a standard 4-level triangular grid (a large triangle divided into 16 unit triangles)?