Conversely, if the base angles of a triangle are equal, then the triangle is isosceles.” In the case of an isosceles triangle that has two equal sides, the equal sides are. This change is seemingly minor, but it means that, by modern standards, equilateral triangles, which have three equal sides, are, a special case of isosceles triangles. Isosceles triangle theorem states that “In an isosceles triangle, the angles opposite to the equal sides are equal. The more modern definition of an isosceles is a triangle with at least two equal sides.Therefore ∆ABC is an Isosceles triangle.Īpplying Pythagoras theorem in ∆ABD, we have If two sides are equal, then the angles opposite to these sides are also equal.įor example, in the following triangle, AB = AC. Now, let us understand the definition of an isosceles triangle.Ī triangle is said to be an Isosceles triangle if its two sides are equal. Also, ancient Babylonian and Egyptian mathematicians were of the know-how on the calculations required to find the ‘ area’ much before the ancient Greek mathematicians started studying the isosceles triangle. The term isosceles triangle is derived from the Latin word ‘īsoscelēs’, and the ancient Greek word ‘ἰσοσκελής (isoskelḗs)’ which means “equal-legged”. The three sides of the triangle above are AB, BC and AC. An exterior angle of a triangle is formed by any side of a triangle and the extension of its adjacent side. The angles opposite to the equal sides of an isosceles triangle are equal. These angles are also called the interior angles of a triangle. An isosceles triangle is a triangle in which two sides are of equal length. The angle formed at A can also be written as ∠BAC. The three angles are the angles made at these vertices, i.e. define isosceles triangle in mathsisosceles triangle equations Isosceles triangle Definition & Meaning - Merriam-Webster. “ īsoscĕles”, in Charlton T.In the above triangles, the three vertices are A, B and C.This word is often used together with triangulum n and rarer with triangulus m.Maybe Latin preserved the short length of the epsilon (ε), or maybe it did not so that the declension became similar to Latin third declension adjectives of one ending (like felix). The Greek masculine and feminine nominative singular is ἰσοσκελής ( isoskelḗs ), while the masculine and feminine vocative singular and the neuter nominative, accusative and vocative singular are ἰσοσκελές ( isoskelés ).Third-declension one-termination adjective (Greek-type).ġIt is unknown if Classical Latin preserved (or would have preserved) the shortness of the original Greek short ending. ( geometry ) isosceles ( having equal legs ).: a percussion instrument consisting of a rod of steel bent into the form of a triangle open at one angle and sounded by striking with a small metal rod. Īsoscelēs ( genitive īsoscelis) third-declension one-termination adjective : a polygon having three sides compare spherical triangle. In a triangle, if two are congruent, the sides opposite them are also congruent. Isosceles Definition & Meaning - Merriam-Webster. In a triangle, if two are congruent, the angles opposite them are also congruent. An isosceles triangle is defined as a triangle having two sides equal. ( īsosceles ) : ( Classical ) IPA ( key): /iːˈsos.ke.les/, Fill in the Blanks with the Words Below Provided Definition: An triangle is a triangle with two congruent sides.( modern Italianate Ecclesiastical ) IPA ( key): /iˈsoʃ.ʃe.les/,.Scalene triangles can have any combination of side lengths as long as they do not form an equilateral triangle (with all sides equal). This results in all the angles being consequently unequal as well. The way that the term isosceles triangle is used in the does not exclude equilateral triangles. A type of triangle in which none of the sides have the same length is called a scalene triangle. ( īsoscelēs ) : ( Classical ) IPA ( key): /iːˈsos.ke.leːs/, The term isosceles triangle is first used in proposition and later in Books II and IV.(1) Since AE is the bisector of side BC, dividing BC equally into BE and EC. Use our isosceles triangle image and see attachment. This property is used to drive the formula for calculating the altitude of an isosceles triangle. Isosceles (disambiguation) on Wikipedia. The altitude of an isosceles triangle bisects its base.Isosceles triangle Definition & Meaning - Merriam-Webster.

Belarusian: раўнабедраны ( raŭnabjedrany ) Definition and examples isosceles right triangle define isosceles.

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