From the setup of the problem, the "length of the top of the bookcase, measured along the attic ceiling" will be the hypotenuse of a right triangle, the length "AB". We have both the angle between AB and AC and the length of AC (3.24 meters), so we can use trigonometric identities.
The cosine of the 40 degree angle between AB and AC is equivalent to the length of AC divided by the length of AB. Equivalently, we have:

where "h", the hypotenuse, is the length we want. Rearranging the formula to solve for h we have that

which is 4.2295... meters. Converting to centimeters (multiplying by 100) we have that h = 422.95... centimeters, or if we round the value, h = 423 centimeters.
Answer:
p = 35
Step-by-step explanation:
Complementary angles sum to 90°
Sum the 2 given angles and equate to 90, that is
20 + 2p = 90 ( subtract 20 from both sides )
2p = 70 ( divide both sides by 2 )
p = 35
Answer:
r = c/x
Step-by-step explanation:
Answer:
18 years old you would be
Answer:
7, I believe. I have to fill in the extra character space, so I hope you have a nice day :)