Explanation:
Since the square is folded along its diagonal,
Perimeter of each triangle
= 2 * Side of square + Diagonal of square.
Side of square
= √(Area of square)
= √(49in²) = 7in.
Diagonal of square
= √(2 * Area of square)
= √(98in²) = 7√2in.
Hence we have 2 * 7in + 7√2in = 7(2 + √2) in.