Answer:
Option D) 38.2
Solution
1) The square section
The side length of the square is 15m.
You can use Pythagoras's theorem to find the length of the diagonal:
Diagonal ^2 = (15m)^2 + (15m^2) = 450 m^2
=> Diagonal = √(450m^2) = 21.21m
2) The small rectangle section
The sides of this rectangle are 23 - 15 = 8 m and 15 m
Now use the Pythagoras's theorem:
diagonal^2 = (8m)^2 + (15m)^2 = 289 m^2 =>
diagonal = √(289m^2) = 17 m
3) Then the sum of the lengths of the diagonals of the two sections is 17m + 21.21 m = 38.21
Answer: 38.21 m