It is a matter of anglesGeometry is the heart of many things that have fueled humanity imagination and technology achievements. Galileo Galilei built plenty of work around the geometrical principle of angles. Perhaps the most fascinating and even the most intriguing since it is leveraged in a lot of pseudo-science movies is the triangle.Angles can be categorized into 5 categories:
- Acute < 90º
- Obtuse > 90º
- Right = 90º
- Straight = 180º
- Reflex > 180ºYou can build different shapes just leveraging different angle sizes. A friend recently applied for a corporate job where he was asked the question “if an analog clock shows 4:20 what’s the angle?”.
He couldn’t answer the question. Here is how I addressed it:The minute hand makes one revolution or 360º every hour.
At 4:00, the minute hand is at 12, its starting point=0º at 12
At 4:20, the minute hand traveled 20/60 or 1/3 of an hour which means1/3 of 360º. The calculator says it’s 120º from the starting point.The hour hand makes one revolution or 360º every 12hours or 30º every hour
At 4:00, the hour hand is at 4, its starting point=120º from 12
At 4:20, the hour hand also traveled 1/3 of an hour which equates to 1/3 of 30º=10ºAt 4:20, the minute hand ended at 120º and the hour hand 120+10=130º from 12.
So the angle between the hour and minute hand when it is 4:20 =130º minus 120º is equal to 10º, therefore, the angle is Acute.So, what’s your angle?! :-)