- The Whetstone River is a 12.7-mile-long (20.4 km) tributary of the Minnesota River, in northeastern South Dakota and a very small portion of western Minnesota in the United States. Via the Minnesota River, it is part of the watershed of the Mississippi River.
- Isosceles triangle (Wikipedia)
In geometry, an isosceles triangle (/aɪˈsɒsəliːz/) is a triangle that has two sides of equal length. Sometimes it is specified as having exactly two sides of equal length, and sometimes as having at least two sides of equal length, the latter version thus including the equilateral triangle as a special case. Examples of isosceles triangles include the isosceles right triangle, the golden triangle, and the faces of bipyramids and certain Catalan solids.