| EQUILATERAL | The type of triangle with sides of the same length and internal angles of the same magnitude |
| NEPAL | Its constitution contains the phrase "on the five angles of the flag the external angles will be equal to the internal angles" |
| RHOMBUS | A quadrilateral with sides of the same length (7) |
| SCALENE | Type of triangle with sides of different lengths |
| ICOSAGON | In geometry, a plane figure with twenty sides and internal angles of 162degrees (8) |
| UNDECAGON | Two-dimensional geometric figure having eleven sides and internal angles of about 147.27degrees (9) |
| ISOSCELES | Type of triangle with two sides of equal length |
| ERATOSTHENES | Greek mathematician and astronomer who calculated the circumference of the earth by observing the angle of the sun's rays (12) |
| NONAGON | A regular one has internal angles of 140 degrees |
| NONAGONS | Regular ____ have internal angles of 140 degrees |
| SNELLSLAW | Formula relating to the angles of incidence and refraction, used in the field of optics (6,3) |
| TRIGONOMETRY | Branch of mathematics dealing with relations between sides and angles of triangles (12) |
| KGB | The intelligence and internal security agency of the former Soviet Union (1,1,1) |
| COUPLET | Two successive lines of verse, usually of the same length (7) |
| EQUINOX | When night and day are of the same length (7) |
| EIGHT | The number of sides and angles of an octagon (5) |
| OFFAL | The entrails and internal organs of an animal, especially those bits considered, by some, to be edib |
| HEADSORTAILS | Two sides of the same coin |
| LACHRYMALGLANDS | Bodily organs at the outer angle of the eyes that secrete tears (9,6) |
| ROAD | One of the courses with sides of rocket salad (4) |
