Question

To measure the perimeter of a curved shape


one needs.

• A. ruler only
• B. thread only
• C. thread and ruler

Answer 1

The correct option is C thread and ruler


Since, the shape is curvy, we cannot measure the boundary length by ruler directly.
$\underset{–}{\text{Steps to measure the perimeter of curved shape:}}$

1. Take a thread/string.
2. Lay it arround the shape tightly once and mark the end.
3. Measure the length of marked thread/string along the ruler.
4. Length of the thread/string gives the perimeter of the shape.

Therefore, to measure the perimeter of an curved shape one needs, thread and ruler.