It seems some part of the text is missing, however, since we are talking about 'crests' I guess we are talking about waves.
In a wave, the distance between two consecutive crests corresponds to the wavelength of the wave. Therefore, the distance measured with the ruler is the wavelength of the wave.
Answer:
1.) 9.9
2.) 15.6
Step-by-step explanation:
1.) Consider triangle AEH
AEH is a right angle triangle as ∠AEH = 90°
AH is the hypotenuse of the triangle.
Applying Pythagorean theorem

substituting values as given in the question:

∴ EH≈9.9
2.) Consider triangle CDF
CDF is a right angle triangle as ∠CDF = 90°
CF is the hypotenuse of the triangle.
Applying Pythagorean theorem

substituting values as given in the question:

∴ DF≈15.6
Answer:
1:55 pm
Step-by-step explanation:
So, you arrive at 4: 15 pm in Orlando after a 2 hr and 20 minute flight from Houston. So, lets start with the easy part: let's subtract the 2 hrs part.
2 hrs earlier from 4:15 pm is 2:15 pm.
Then, you have to subtract the 20 minutes. Well, it's quite obvious that if you left at 2:00 pm, that would be a total of 2 hrs and 15 minutes. Just subtract the 15 minutes from the 2:15 pm. However, it's 20 minutes, not 15, so you have to still subtract that last five minutes.
So, 2:00 pm minus 5 minutes would equal 1:55 pm.
Answer:

Step-by-step explanation:
For this, you check to see if any of these variables are the same. There are two x's, and 2 y's. So, you have to multiply x and x, which gives you 2x, and since you multiply the y's it will give you y^2.
So the answer will be 
Answer:
x = 3
Step-by-step explanation:
8 - 2x = 2
- 2x = 2 - 8
- 2x = - 6
- x = - 6/2
- x = - 3
x = 3