 Let us talk about altitudes of triangles. Altitudes of triangles is basically the height of the triangle and Imagine if any triangle is kept on a table If we just measure the height of it that is the length of altitude How do we identify this altitude because this is the height it is perpendicular to the base of the triangle and because We have kept this triangle on some surface like a table This is the distance between the base and the topmost point of the triangle and so an altitude is Basically a perpendicular dropped from any vertex to the opposite side and because it's perpendicular The angle that an altitude makes with the side of the triangle is 90 degrees Now what if we rotated this triangle if we rotated this triangle keeping this side as the base now The height of the triangle will will change now. This is the table base and We will drop a perpendicular from the opposite vertex to the opposite side And that will be the height of the triangle now and this is 90 degrees So I'll just label it as h1 and now let's rotate this triangle again keeping this side as the base We get something like this and now here the table is here with this side and the height of this is this like like this and The altitude length is much larger in this case as you can notice so it's basically drawing a perpendicular from the Vertex the topmost point to the opposite side and so we just saw we can draw three Altitudes for the given triangle and their lengths are different We can always name these altitudes by different points So let's say this altitude is a m in here The triangle is rotated like this ABC and this altitude is CN and in this triangle We have the triangle placed like this and the perpendicular drop could be called be you there are different kinds of triangles as well One of the triangles that we can think about is an acute angle triangle where all the angles are acute And so all the altitudes are Inside the triangle. So this is acute angle triangle But what about when we have an obtuse angle triangle where one of the angles is an obtuse angle If we have a triangle like this the height of this triangle can be found by dropping the altitude from this vertex to the opposite side But when we try to do that, you have to extend the side of the triangle, which is at the base of it So we could just name this triangle as ABC and this BC is extended up to D and AD is then the altitude Rest of the altitudes are CE or say BF which can be drawn like this by extending the opposite side And this is how you can identify the altitudes of an obtuse angle triangle Another kind of a triangle that we know of is a right angle triangle itself and in right angle triangle one of the altitudes Is itself a side So here AB is perpendicular to BC and that's also an altitude of the triangle And you can try drawing altitude from B to AC like this and then CB is also an altitude To AB we just name this point as N. So for every triangle just remember that you have to drop A perpendicular from a given vertex to the opposite side in order to get the altitude of the triangle