Perimeter of rectangle : Perimeter of square = 10 : 7.
Side of square = 14 cm.

• Perimeter of square = 4 × 14 = 56 cm
• Let 7 units = 56 cm → 1 unit = 8 cm
• Perimeter of rectangle = 10 units = 10 × 8 = 80 cm

The perimeter of the rectangle is 80 cm.
Check: 80 : 56 = 10 : 7. ✓