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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Cosine rule uses trigonometric SAS triangle calculator.
See also our trigonometric triangle calculator.
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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