One hypothesis about the shape of the universe is that the universe is in the space of Euclidean geometry and flat. In Euclidean geometry, it is assumed that straight lines extend everywhere, planes ...

Everyone learns the number one rule about triangles in high school: the angles of a triangle add up to 180 degrees. But did you know that sometimes they don't? Triangles are much more interesting than ...

View Wall Drawing 356 B, An isometric triangle outlined by 3-inch 7.5 cm bands. Within each plane are 3-inch 7.5 cm wide black bands of parallel lines in one of three directions. by Sol LeWitt on ...

A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. The dashes on the lines show they are equal in length. The angles at the ...

Parallel lines close parallel lines Lines which never meet and stay the same distance apart. Parallel lines are indicated by a pair of arrows. are two or more straight lines that remain the same ...