Answer:
3) 16.2
Step-by-step explanation:
The supplement to the 115° angle on the right is 65°, the same as the angle at upper left. The vertical angles at C are the same measure, so this tells you that the two triangles FCB and ACD are similar by the AA similarity postulate. That being the case, corresponding sides are proportional:
CB/CD = CF/CA
CB = CD·CF/CA = 7.2·21.6/9.6
CB = 16.2
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When given two "point-to-point" triangles like this, quite often there is some sort of similarity relationship involved. First, you need to figure out what it is; then you need to make use of it as needed to answer the question being asked.
Answer:
The guard should be positioned at the safe
Step-by-step explanation:
The night watchmen should be positioned to guard whichever place gives the highest expected value to the thief.
The expected value of robbing the safe is:

The expected value of robbing the cash register is:

Therefore, the guard should be positioned at the safe since it yields a higher expected value to the thief in case he tries to rob it.
Answer:
y = 9
Step-by-step explanation:
1) Multiply both sides by 3.
3 × 3 = y
2) Simplfiy 3 × 3 to 9.
9 = y
3) Switch sides.
9