Triangles

How Do You Prove Triangles Are CongruentCongruent FiguresTwo figures/objects are said to be congruent if they are exactly of the same shape and size. The relationship between two congruent figures is called congruence. We use the symbol ≅…

How Do You Find The Angle Of An Isosceles Triangle Theorem: Angles opposite to equal sides of an isosceles triangle are equal. Given: In ∆ABC, AB = AC To Prove: ∠B = ∠C Construction: Draw AD, bisector of ∠A ∴ ∠1 = ∠2 Proof: In ∆ADB &…

Pythagoras TheoremTheorem 1: In a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. Given: A right-angled triangle ABC in which B = ∠90º. To Prove: (Hypotenuse)2 = (Base)2 +…

Criteria For Congruent TrianglesCongruent triangles are triangles that have the same size and shape. This means that the corresponding sides are equal and the corresponding angles are equal.Congruent Triangles do not have to be in the same…

Classification of TrianglesA triangle is a polygon with three sides. It has three sides and three vertices. There are seven types of triangles. The sum of the angles of a triangle is 180°.Triangles Types can be classified in two ways:By…

Theorems and Postulates for GeometryThis is a partial listing of the more popular theorems, postulates and properties needed when working with Euclidean proofs. You need to have a thorough understanding of these items.General:Reflexive…

Theorems and Postulates for GeometryThis is a partial listing of the more popular theorems, postulates and properties needed when working with Euclidean proofs. You need to have a thorough understanding of these items.General:Reflexive…

Criteria For Similarity Of TrianglesAAA similarity criterion: If in two triangles, corresponding angles are equal, then the triangles are similar. AA Similarity criterion: If in two triangles, two angles of one triangle are respectively…

Criteria For Similarity Of TrianglesAAA similarity criterion: If in two triangles, corresponding angles are equal, then the triangles are similar. AA Similarity criterion: If in two triangles, two angles of one triangle are respectively…

Areas Of Two Similar TrianglesTheorem 1:  The ratio of the areas of two similar triangles are equal to the ratio of the squares of any two corresponding sides. Given: Two triangles ABC and DEF such that ∆ABC ~ ∆DEF. To Prove:  (frac{Area…