Identify \(\text{every}~\text{card}\) with a perimeter or circumference of \(24~\text{units}\).
Cards:
• A rectangle with side lengths \(8~\text{units}\) and \(4~\text{units}\)
• A square with side length \(6~\text{units}\)
• A triangle with side lengths \(7~\text{units}\), \(9~\text{units}\), and \(8~\text{units}\)
• A circle with radius \(4~\text{units}\)
• The expression \(2(5~+~7)\)
• A garden where the distances around the \(\text{four}~\text{sides}\) are \(10~\text{ft}\), \(2~\text{ft}\), \(10~\text{ft}\), and \(2~\text{ft}\)
• A regular pentagon with side length \(5~\text{units}\)
What this problem is really about
Treat the target boundary value as a test that every representation must pass independently. Add all outside sides for polygons and contextual figures, evaluate any given expression with its grouping intact, and use the circumference formula when a radius is supplied. Exact equality matters, so an approximation near the target does not count as a match.