The Battle of Fredericksburg was fought December 11â15, 1862, in and around Fredericksburg, Virginia, between General Robert E. Lee 's Confederate Army of Northern Virginia and the Union Army of the Potomac, commanded by Major General Ambrose Burnside.
In an isosceles triangle that has exactly two equal sides, the equal sides are called legs and the third side is called the base. The angle included by the legs is called the vertex angle and the angles that have the base as one of their sides are called the base angles.
If we define an isosceles triangle as one in which strictly two sides are of equal length then, no, an equilateral triangle is not isosceles. On the other hand, if we define an isosceles triangle as one for which there exists a pair of sides of equal length then, yes, an equilateral triangle is isosceles.