10 most difficult geometry riddles A list of geometry related questions that are most often answered incorrectly Mathematics quiz During a full 24-hour day, how many times would the hands of a clock overlap?22. The minute hand makes 24 revolutions, while the hour hand makes 2 revolutions.very hard 32% 666%121221%222232%242439%Created by: globalquiz.org. Statistics based on 6146 answers in 2 languages »time riddles » What is the maximum distance a plane can fly travelling constantly North?20,004 km. Continous travel North must eventually end at the North Pole. So, the maximum distance is half of the Earth's meridional circumference, which can be reached if a plane starts at the South Pole.hard 42% 10,002 km10,002 km9%20,004 km20,004 km42%40,007 km40,007 km17%It can fly endlessly (as long it can)It can fly endlessly (as long it can)29%Created by: globalquiz.org. Statistics based on 11328 answers in 2 languages »aviation riddles » If Earth's radius was larger by 1 meter, how much longer would its equator be?By approx 6 meters. For each circle, the length of the circumference is c=2πr. Hence, if a radius grows by 1 meter, the circumference grows by 2 π meters - no matter what the initial value of radius was.hard 44% by approx 6 metersby approx 6 meters44%by approx 6 kilometersby approx 6 kilometers17%by approx 60 kilometersby approx 60 kilometers21%by approx 6000 kilometersby approx 6000 kilometers16%Created by: SpikeMe. Statistics based on 14783 answers in 2 languages »Earth riddles » What is the volume of a soap bubble with radius R=1 cm?4/3π cm3. Equation for the volume of a sphere: 4/3πR^3.hard 57% 3/4π cm33/4π cm320%4/3π cm34/3π cm357%4,3π cm34,3π cm310%It isn't possible to calculateIt isn't possible to calculate11%Created by: Paweł Kołodziejczyk. Statistics based on 7647 answers in 2 languages »numbers riddles » Which shape is larger?None of them. Both shapes are the same, but the bottom one is placed more to the right. This is however difficult to notice. It is known as Jastrow Illusion.average 61% AA3%BB20%None of themNone of them61%Both are largerBoth are larger14%Created by: globalquiz.org. Statistics based on 20485 answers in 4 languages »illusions riddles » Which direction is not possible to point at when standing at the South Pole?Neither east, west, nor south. At the South Pole every direction is north.average 68% easteast2%westwest2%northnorth25%neither east, west, nor southneither east, west, nor south68%Created by: globalquiz.org. Statistics based on 12856 answers in 2 languages »Antarctic riddles » Which lines are parallel?Green, blue and red. This is a well known Zöllner illusion, first described in 1860. It may be caused by this impression of depth. The black lines are parallel, too!average 69% blue and red onlyblue and red only5%green and red onlygreen and red only9%green, blue and redgreen, blue and red69%nonenone15%Created by: globalquiz.org. Statistics based on 12163 answers in 2 languages »optical illusions riddles » How many edges does a Möbius strip have?One. The Möbius strip is a surface with only one side and only one boundary component (edge). A line drawn starting from the seam down the middle will meet back at the seam but at the "other side". If continued the line will meet the starting point and will be double the length of the original strip.easy 73% oneone73%twotwo18%threethree4%fourfour3%Created by: globalquiz.org. Statistics based on 11337 answers in 4 languages »math riddles » How is this polygon called? (the one over the circles)Square. In this Ehrenstein illusion the sides of a square placed inside a pattern of concentric circles take an apparent curved shape. But in reality, the sides are straight.easy 75% squaresquare75%rhomboidrhomboid10%concave squareconcave square8%concave rhomboidconcave rhomboid5%Created by: Debbie Fox. Statistics based on 22144 answers in 2 languages »mathematics riddles » How many degrees an obtuse angle can have ?90-180. The obtuse angle may measure from 90 to 180 degrees. Angles having a degree of 0 to 90 are acute angles, whereas those from 180 to 360 - concave angles.easy 77% 0-3600-3603%90-18090-18077%0-900-902%180-360180-36016%Created by: TotalBellend. Statistics based on 6831 answers in 2 languages »mathematics riddles » Play mathematics quiz and see all the questions.