Answer:
Your answer will be D. He knows that 30 × 16 is 5 then multiples 5 by 5 to get 25.
I think the answer is C 1 2/3
It appears that the Pythagorean theorem can be applied to this problem
(distance to shadow)² = (height of building)² + (length of shadow)²
(38 m)² = (height of building)² + (28 m)²
660 m² = (height of building)²
Then the height of the building is
height of building = √660 m ≈ 25.7 m
