When two straight lines cross, the opposite angles they form (vertical angles) are always what?
AnswerEqual
Vertical angles are congruent, always equal in measure.
Science · Facts & stats
Vertical facts & stats
7 fact-checked facts about vertical farming, tall structures and the geometry of up, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
In which city is the Burj Khalifa?
AnswerDubai
The Burj Khalifa opened in Dubai in 2010.
Going deeper
Many vertical farms grow plants without soil, in nutrient-rich water. What is this method called?
AnswerHydroponics
Hydroponics feeds roots with nutrient solutions instead of soil.
In what year was the Empire State Building completed?
Answer1931
The Empire State Building opened in 1931 after about 13 months of construction.
What tool shows level or plumb using a bubble in a liquid-filled vial?
AnswerSpirit level
A spirit level's bubble centers when a surface is level or plumb.
Expert level
Which Columbia University professor popularized the modern idea of vertical farming?
AnswerDickson Despommier
Despommier developed and promoted the vertical farm concept in the late 1990s and 2000s.
Roughly how tall is the Burj Khalifa?
AnswerAbout 828 meters
The Burj Khalifa reaches about 828 meters, or 2,717 feet.
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