The most difficult mathematics is that which you do not know. A surprising amount of mathematics is actually easy once you've learned it. Of course, once you learn the easy stuff, then you have to start tacking the deep stuff, and that gets harder.
An isosceles triangle has two sides of equal length. An isosceles triangle also has two angles of the same measure; namely, the angles opposite to the two sides of the same length; this fact is the content of the isosceles triangle theorem, which was known by Euclid.
Isosceles triangle is a triangle in which two sides are of equal length and two angles are of equal measure. Scalene triangle is a triangle which has all sides of different length and all angles are of different measure. Now we will see how many angles does a triangle have. As we know that a triangle has 3 sides and 3 vertices and each vertex has one angle in them and therefore there are total of 3 angles in a triangle.