Solution:
Step-1: Find the missing side length using Pythagoras theorem:
- 115² = 69² + x²
- => 13225 = 4761 + x²
- => 13225 - 4761 = x²
- => 8464 = x²
- => x = √8464 = 92
Step-2: Find the area of the rectangle:
- Area of rectangle = LB
- => 69 x (92 + 100)
- => 69 x 192
- => 13248 units²