Isosceles triangles have Isosceles triangles have two sides equal. Isosceles triangles have two sides equal. triangle Isosceles triangles have two sides equal. two equal sides B Which triangle looks like an isosceles triangle? C A ∆ABC ∆EFD ∆XYZ F D E Z X Y 5 In an isosceles triangle In an isosceles triangle isosceles triangle In an isosceles triangle the base angles In an isosceles triangle base angles the base angles In an isosceles triangle the base angles are equal. In an isosceles triangle the base angles are equal. In an isosceles triangle the base angles are equal. In an isosceles triangle the base angles are equal. equal angles B C A Which angles are base angles? ∡A and ∡C ∡B and ∡A ∡B and ∡C Base angles are equal not equal An easy way to determine which angles An easy way to determine which angles are the base angles: An easy way to determine which angles highlight where the equal sides meet are the base angles: An easy way to determine which angles highlight where the equal sides meet are the base angles: isosceles triangle An easy way to determine which angles highlight where the equal sides meet are the base angles: equal sides An easy way to determine which angles highlight where the equal sides meet are the base angles: An easy way to determine which angles highlight where the equal sides meet are the base angles: An easy way to determine which angles highlight where the equal sides meet are the base angles: equal sides meet here An easy way to determine which angles highlight where the equal sides meet are the base angles: This is the 'roof' of the triangle An easy way to determine which angles highlight where the equal sides meet roof are the base angles: This is the 'roof' of the triangle An easy way to determine which angles highlight where the equal sides meet are the base angles: This is the 'roof' of and the base angles the triangle are at the bottom An easy way to determine which angles highlight where the equal sides meet are the base angles: angles base This is the 'roof' of and the base angles the triangle are at the bottom Identify the 'roof' A ∡ C B ∡ X Z Y Q N M ∡ ∡ R P L Roof ? Base ? An equilateral triangles has all the sides equal An equilateral triangles has all the sides equal Equilateral Triangle An equilateral triangles has all the sides equal An equilateral triangles has all the sides equal An equilateral triangles has all the sides equal 8 Since all the sides are equal Since all the sides are equal equal sides Since all the sides are equal then the angles must be equal as well Since all the sides are equal then the angles must be equal as well Since all the sides are equal then the angles must be equal as well Since all the sides are equal then the angles must be equal as well Since all the sides are equal then the angles must be equal as well Equal Angles That means each angle must be 60∘ in an Since all the sides are equal then the angles must be equal as well equilateral triangle ∘ ∘ ∘ Each angle in an equilateral triangle is ∘ |