Isosceles Triangles. Isosceles Triangles Base Angles If 2 angles in a triangle are congruent, then the sides opposite them are congruent.

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Presentation transcript:

Isosceles Triangles

Base Angles If 2 angles in a triangle are congruent, then the sides opposite them are congruent.

Solve for x. 2x + 25 = 7 2x = -18 12 x = -9

Base Angles If 2 sides in a triangle are congruent, then the angles opposite them are congruent.

Solve for x. 6x + 1 = 55 6x = 54 3 x = 9

The measure of the exterior angle is equal to the sum of two nonadjacent interior angles (Remote Interior Angles: <1 and <2) 1 m1+m2 =m3 2 3 Essential Question: How do the external angles of a triangle relate to the two remote interior angles?

Find the value of x. 430 x 380 Essential Question: How do the external angles of a triangle relate to the two remote interior angles?

Find the value of x. 720 1480 x0 Essential Question: How do the external angles of a triangle relate to the two remote interior angles?

Find the value of x. Essential Question: How do the external angles of a triangle relate to the two remote interior angles?