The image shows a portion of a bridge supported by two vertical pillars built from the points B and C on the slope below. The length of the bridge between pillar B and pillar C is BLANK feet.
Accepted Solution
A:
In order to find the length of ?? (let's call this distance x), let's first find the value of Angle A.
The cosin of Angle A is Adjacent / Hypotenuse, or 40 / 50. Using this Info: cos (A) = 40/50 cos (A) = .8
With this crucial piece of info, we can find the Total length of A-D (Point D being the point above C), by finding its relation to side AC (length of 50 + 70 =120 ft) Cos (A) = adjacent / hypotenuse Cos (A) = AD / (120) We know that cos (A) = .8 .8 = AD / (120) Multiply both sides by 120 96 = AD
We're almost there! Remember that we're trying the find x (?? in the diagram).