[bdc641]

A wooden plank is leaning against a wall. The bottom of the plank is 3 feet from the wall. Answer each of the following questions, and show your work.
a) Find AC, the approximate length of the plank. Round to the nearest tenth of a foot.
b) Find BC, the height off the ground where board touches the wall. Round to the nearest foot.

The sketch is as follows: right angle; two 45 degree angles; AC is opposite the right angle (hypotenuse)

Your assistance is greatly appreciated.

[georgec1960]

The trick is knowing the equation and a little algebra
you have the adjacent side with the 3
so cosine A = adj/ hyp
Cosine of 45 degrees =.707 so .707= 3/hyp
work some algebra magic and 3/.707= 4.24 that is the hyp
you pretty much know that the opposite side is the same as the adjcent but lets play
SinA= opp/hyp sine of 45degrees is .707
so .707= opp/ 4.24 play with the ALGEBRA and answer is 3
side A and side B are 3 and hyp is 4.24