A horse is tethered to one corner of a rectangular grassy field 45 m by 25 m with a rope 22 m long. Over how much area of the field can it graze?
Answers
A) 354 cm 2	B) 380 m 2	C) 350 m 2	D) 407 m 2	E) none of these

Rationale: "area of the shaded portion = 1 ⁄ 4 × π × ( 22 ) 2 = 380 m 2 answer b"
Answer: B