Answer:
Length of the other side of the backyard is 80.4 feet.
Explanation:
Let the dimensions of the Liam's rectangular backyard = 85 feet × a feet
Diagonal of the rectangle, AD = 117 feet
When we apply Pythagoras theorem in ΔABD,
AD² = AB² + BD²
(117)² = (85)² + BD²
a² = 13689 - 7225
a = √6464
= 80.399 feet
a ≈ 80.4 feet
Therefore, length of the other side of the backyard is 80.4 feet.