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4.5 Isosceles and Equilateral Triangles. Chapter 4 Congruent Triangles. 4.5 Isosceles and Equilateral Triangles. Isosceles Triangle:. Vertex Angle. Leg. Leg. Base Angles. Base. *The Base Angles are Congruent*. Isosceles Triangles. Theorem 4-3 Isosceles Triangle Theorem
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4.5 Isosceles and Equilateral Triangles Chapter 4 Congruent Triangles
4.5 Isosceles and Equilateral Triangles Isosceles Triangle: Vertex Angle Leg Leg Base Angles Base *The Base Angles are Congruent*
Isosceles Triangles • Theorem 4-3 Isosceles Triangle Theorem If two sides of a triangle are congruent, then the angles opposite those sides are congruent B <A = <C A C
Isosceles Triangles • Theorem 4-4 Converse of the Isosceles Triangle Theorem If two angles of a triangle are congruent, then the sides opposite those angles are congruent B Given: <A = <C Conclude: AB = CB A C
Isosceles Triangles • Theorem 4-5 The bisector of the vertex angle of an isosceles triangle is the perpendicular bisector of the base B Given: <ABD = <CBD Conclude: AD = DC and BD is ┴ to AC A C D
Equilateral Triangles • Corollary: Statement that immediately follows a theorem Corollary to Theorem 4-3: If a triangle is equilateral, then the triangle is equiangular Corollary to Theorem 4-4: If a triangle is equiangular, then the triangle is equilateral
Using Isosceles Triangle Theorems Explain why ΔRST is isosceles. T U Given: <R = <WVS, VW = SW Prove: ΔRST is isosceles R W V S
Using Algebra Find the values of x and y: M ) ) y° N x° O 63° L
Landscaping A landscaper uses rectangles and equilateral triangles for the path around the hexagonal garden. Find the value of x. x°
Practice • Pg 213 1-16, 21-26