We know the lenght of the side adjacent to angle A, AC, and we want to know the opposite side, BC. What trig ratio describes the relationship between opposite and adjacent? The Tangent!
tan (x) = opp / adj
In this case, tan (45°) = BC / 4
To get BC by itself, multiply both sides by 4
4 * tan (45°) = BC
The answer is D
Shawn can complete a concrete job in 4 hours, in one hour he will do 1/4 of the job.
Ellie can complete a concrete job in 6 hours, in one hour he will do 1/6 of the job.
If Shawn and Ellie work together, they will complete 1/4 + 1/6 of the job in one hour, that is,
Amount of work done by both workers in an hour = 1/4 + 1/6 = 5/12.
5/12 = 1/x, where x is the number of hours required to complete the job by both men
5/12 = 1/x
Cross multiply:
5 * x = 12 * 1
5x = 12
x = 12/5 = 2.40
Therefore, if the two men are working together, it will take them 2.40 hours to complete the job.
Answer:
C. 12/15 is not equivalent to the rest
Step-by-step explanation:
12/15 simplifies to 4/5, whereas all the others simplify to 2/3
