Answer:
√10 feet ≈ 3.2ft
Step-by-step explanation:
If the helght of the bench's back is 3 feet tall and the width of the bench's seat Is 1 foot long, the length of the arm will be gotten using the pythagoras theorem;
Let l be the required length, Hence;
l² = 3² + 1²
l² = 9 + 1
l² = 10
Square root both sides
√l² = √10
l = √10 feet
Hence the length of the arm is √10 feet