Answer:
1.
2. 13.5 +
3.
6.
These four options are rational;
Step-by-step explanation:
1. equals to 10 * 10 = 100 which is rational
2. 13.5 + equals 13.5 + 9 = 22.5
3. -- 3+27 = 30
6.
Option 4 and 5 are irrational because they include and
which are not a perfect square and their answers will be non recurring and non terminating decimal fraction.
Answer: The answer is 381.85 feet.
Step-by-step explanation: Given that a window is 20 feet above the ground. From there, the angle of elevation to the top of a building across the street is 78°, and the angle of depression to the base of the same building is 15°. We are to calculate the height of the building across the street.
This situation is framed very nicely in the attached figure, where
BG = 20 feet, ∠AWB = 78°, ∠WAB = WBG = 15° and AH = height of the bulding across the street = ?
From the right-angled triangle WGB, we have
and from the right-angled triangle WAB, we have'
Therefore, AH = AB + BH = h + GB = 361.85+20 = 381.85 feet.
Thus, the height of the building across the street is 381.85 feet.
