The length and breadth of a rectangle are in the ratio 3:1. If the breadth is 7 cm, then the length of the rectangle is:

🧠 Explanation:

A rectangle with a 3:1 length-to-breadth ratio and breadth of 7 cm has a length of 21 cm. Calculate: 1 part = 7, so 3 parts = 3 × 7 = 21. This teaches students ratio calculations, useful in geometry or real-world measurements. Understanding ratios helps with tasks like designing spaces or scaling objects. For students, this skill is key for math exams or practical scenarios like construction or art, ensuring accurate measurements for projects or planning where proportions are critical.