1598 Spanish Colonization of New Mexico Juan de OÃ±ate leads the Spanish colonization of the province of New Mexico. He establishes his first capital in San Juan de los Caballeros at the confluence of the Rio Grande and Chama River. Read More.
1 An equilateral triangle has all its angles measuring 60Â°. So, the angles of an equilateral triangle are Congruent Angles.  A square and a rectangle have all their angles measuring 90Â°. So, the angles of a square and a rectangle are Congruent Angles.
We mark the congruent sides by a slash mark. The angles in an equilateral triangle are always 60Â°. When a triangle has two congruent sides it is called an isosceles triangle. The angles opposite to the two sides of the same length are congruent. A triangle without any congruent sides or angles is called a scalene triangle. When two triangles are congruent it means that they have the same size and shape. This means that they have the same angles.