Thread: Circular Problems

Given a pole 2 m high, and 30 cm in circumference. A ribbon winds around it 7 times from its base to its top. Find the length of the ribbon?

Given a circular log, 2 metres 50 centimetres in diameter. Assume it is turned into a rectangular plank 70 centimetres thick. Find the possible maximum width of the plank?

How does one solve these word problems.

Thanks in advance,

Raymond MacNeil

Originally Posted by raymac62

Given a pole 2 m high, and 30 cm in circumference. A ribbon winds around it 7 times from its base to its top. Find the length of the ribbon?
...
How does one solve these word problems.

Thanks in advance,

Raymond MacNeil

1. Draw a sketch.

2. The length of the ribbon is the hypotenuse of a right triangle whose legs are the length of the pole and 7 times the circumference of the pole. Use Pythagorean theorem.

3. You should come out with 2.9 m.

Originally Posted by raymac62

...

Given a circular log, 2 metres 50 centimetres in diameter. Assume it is turned into a rectangular plank 70 centimetres thick. Find the possible maximum width of the plank?

How does one solve these word problems.

Thanks in advance,

Raymond MacNeil

1. Draw a sketch.

2. You are dealing with a right triangle. (see attachment) Use Pythagorean theorem.

3. You should come out with w = 2.4 m

Thank you sir or madam.

Dear earboth,
According to Dr Math your right triangle base should by increased by another circumference. This would make the ribbon 3.12m. Is he wrong?

bjh