A dam needs a supporting beam. The dam leans at an 80 degree angle and is 200 feet tall. If the base of the supporting beam is placed 75 feet from the base of the dam and the beam extends to the top of the dam, how long must the beam be?

Question

anonymous · Answer

Do you think you can draw this problem?

anonymous · Answer

and post it?

anonymous · Answer

is it this?|dw:1398344955642:dw|

anonymous · Answer

Do you know the law of cosines?

Well it says that:$$c^2=a^2+b^2-2abcos \theta$$

c is the side opposite the angle:$$\theta$$

and a and b are the sides adjacent to the angle



In this case c is x, Ø is 80 degrees,a is 200, and b is 75


so plug that into the law of cosines to solve for x.

anonymous · Answer

so $$x^2=(200)^2+(75)^2-2•200•75•\cos(80º)$$

anonymous · Answer

so solve for x

anonymous · Answer

remember the law of cosines @Bella_Q