Question

A wire is bent to form a circle of radius 7 cm. From the resulting shape, a chunk of the wire is cut off, and the wire cut off measures 4 cm in length. Find the length of the remaining wire (in cm).

• A. 20 cm
• B. 40 cm
• C. 60 cm
• D. 80 cm

Answer 1

The correct option is B 40 cm

The length of the wire = circumference of the circle with radius 7cm
$=2\times \pi \times r=2\times \frac{22}{7}\times 7=44$ cm.
When a wire of length 4 cm is cut off, the length of the wire remaining = circumference - length of arc cut off = 44 - 4 = 40 cm.