A triangle is a regular polygon and the closed two-dimensional figure having 3 sides, 3 vertices, and 3 angles. The sum of interior angles adds up to 180 – degree and the sum of the exterior angles would make up 360-degrees.
Three most popular triangles based on the side length are given as –
In this post, we will discuss the isosceles triangle formula and its area and the perimeter.
An isosceles triangle is a polygon having two equal sides and two equal angles adjacent to equal sides. Let us discuss further how to calculate the area, perimeter, and the altitude of an isosceles triangle.
From the figure let a is the side equal for an isosceles triangle, b is the base and h, is the altitude. Then the area of an isosceles triangle formula can be given as –
\[Area\;of\;Isoscele\;Triangle =\frac{1}{2}bh\]
\[Altitude\;of\;an\;Isosceles\;Triangle=\sqrt{a^{2}-\frac{b^{2}}{4}}\]
Where,
b = Base of the isosceles triangle
h = Height of the isosceles triangle &
a = length of the two equal sides
Let us have a quick look at the properties of an isosceles triangle for a better understanding of the concept. These are –
As discussed earlier, an isosceles triangle has two equal sides and two equal internal angles. If you know the two equal sides and the base side of a triangle then calculating perimeter is easy. The isosceles triangle perimeter formula is given as –
\[\large Perimeter\;of\;Isosceles\;Triangle,P=2\,a+b\]
Where,
a = length of the two equal sides
b = Base of the isosceles triangle