A triangle is written of 3 line segments. The heat segments crossing in your endpoints. To surname a triangle we often use the vertices (the surname of the endpoints). The triangle listed below is called ABC.

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

We have actually different species of triangles. A triangle is divide by its angles and by the variety of congruent sides.

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

See more: 2005 Dodge Durango Electronic Throttle Control Light Is Blinking When 2 triangles space congruent it means that they have the very same size and also shape. This way that they have the exact same angles. The red cut marks show us i beg your pardon sides and also angles that room congruent Congruency is displayed by this symbol

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

Triangles that have congruent angles but not the same size are dubbed similar. Similar triangles have sides that are proportional. Similarity is displayed 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 comparable the sides room proportional which way that

\$\$fracx14=frac321Rightarrow\$\$

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

\$\$x=2\$\$

## Video lesson

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