A triangle is created of 3 line segments. The line segments intersect in your endpoints. To name a triangle we often use its vertices (the name of the endpoints). The triangle listed below is named ABC.

You are watching: What is a triangle with two congruent sides A triangle has actually three angles. The sum of the actions of the angles is always 180° in a triangle.

We have actually different varieties of triangles. A triangle is classified by that angles and by the number of congruent sides.

A triangle that has actually three acute angels is referred to as an acute triangle. A triangle that has one right angle is dubbed a appropriate triangle. A triangle that has one obtuse angle is dubbed an obtuse triangle. When a triangle has three congruent sides, we call the triangle an it is intended triangle. We note the congruent sides by a slash mark. The angles in an equilateral triangle are always 60°. When a triangle has actually two congruent political parties it is dubbed an isosceles triangle. The angle opposite come the 2 sides that the same size are congruent. A triangle without any type of congruent political parties or angle is called a scalene triangle.

See more: How Many Quarters Can Fit In A 2 Liter Bottle ? How Many Quarters Are In A 2 Liter Bottle When two triangles space congruent it way that they have actually the exact same size and also shape. This method that they have the very same angles. The red slash marks show us i m sorry sides and angles that are congruent Congruency is presented by this symbol

\$\$cong\$\$ \$\$eginmatrix Acong X & & ABcong XY\ Bcong Y & & BCcong YZ\ Ccong Z & & ACcong XZ endmatrix\$\$

Triangles that have congruent angles yet not the exact same size are dubbed similar. Comparable triangles have sides that are proportional. Similarity is presented by this symbol

\$\$sim\$\$ \$\$igtriangleup ABCsim igtriangleup XYZ\$\$

\$\$A=X,: : B=Y,: : C=Z\$\$

\$\$fracax=fracby=fraccz\$\$

Example

Find x in the similar triangles. We know that due to the fact that the triangles are similar the sides space proportional which way that

\$\$fracx14=frac321Rightarrow\$\$

\$\$x=frac14cdot 321=frac4221=2\$\$

\$\$x=2\$\$

## Video lesson

Find out whether the triangles space right, isosceles, acute, scalene, obtuse or equilateral