What is the isosceles triangle’s unknown angle x? The buildings in the shape of an isosceles triangle are not only attractive but earthquake-resistant as well.Įxample 1) Given below is a figure of an equilateral triangle(ABC) and an isosceles triangle (ABD) where DA=DB. In Latin, the word isosceles is written as “ ‘īsoscelēs,’ and in Greek, the word isosceles is written as ‘ἰσοσκελής (isoskelḗs).’ In both Latin and Greek, the meaning of the word ‘isosceles’ means “equal-legged”.Įven before the Greek mathematician could study the isosceles triangle, the Babylonian and Egyptian already knew how to calculate the area od an isosceles triangle. In the case of an isosceles triangle, we know the two sides of it are equal, so the formula for finding the perimeter an isosceles triangle can be modified as 2a + c if the sides are a, b, and c. To find the perimeter, we just have to add all the sides of the triangle, i.e., side 1 + side 2 + side 3. We have a straightforward and familiar formula to find the perimeter of isosceles triangle. Just like finding the perimeter of any other figure is easy, the perimeter of isosceles triangle is also very easy. Therefore, we can use the following formula to find the area of an isosceles triangle. Since in an isosceles triangle, we know that the two sides of it are equal and the base of the triangle is the unequal one. The formula to calculate the area of isosceles triangle is: There are two formulas for an isosceles triangle, one is to find the area of the triangle, and the other is to find the perimeter of an isosceles triangle. The sides of the triangle form the chords of the circumcircle. The unequal angle or the base of the triangle is either an acute or obtuse angle.

To find the perimeter of the triangle we just have to add up all the sides of the triangle. The formula to find the area of isosceles triangle or any other triangle is: ½ × base × height. In an isosceles triangle, the height that is drawn from the apex divides the base of the triangle into two equal parts and the apex angle into two equal angles. The side of the triangle that is unequal is called the base of the triangle. In an isosceles triangle, the two sides are congruent to each other. So here are the properties of a right-angled triangle. Now that we know what a triangle and an isosceles triangle is, it’s best if we move on the question, what are the properties of an isosceles triangle. What are the Properties of an Isosceles Triangle? Here, given below, is an example of a right-angled triangle.

As we already know that the sum of all the angles of a triangle is always 180, so if two of the sides of a right-angled triangle are known to us, we can find the third side of the triangle. Therefore, the two opposite sides in an isosceles triangle are equal. If two out of three sides of a triangle have equal length, then the triangle will be called an isosceles triangle. Triangles are classified into two categories based on their side and angle. We should also know that the sum of all the interior angles of a triangle is always 180 degrees. Those three line segments are the sides of the triangle, the point where the two lines intersect is known as the vertex, and the space between them is what we call an angle. We can draw a triangle using any three dots in such a way that the line segments will connect each other end to end. It is the basic or the purest form of Polygon. A triangle is a 2-dimensional closed figure that has three sides and angles.

Height of an isosceles triangle formula