# Big tower

From the tower, which is 15 m high, and 30 m from the river, the river's width appeared at an angle of 15°. How wide is the river in this place?

### Correct answer:

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Try conversion angle units angle degrees, minutes, seconds, radians, grads.

#### You need to know the following knowledge to solve this word math problem:

**planimetrics**- right triangle
- triangle
- The Law of Cosines
- The Law of Sines
**goniometry and trigonometry**- tangent
- arctangent

#### Units of physical quantities:

#### Grade of the word problem:

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