Atriangle with the sides 6,8 and 10 . what kind of triangle is it ?

It would be right-angled Triangle.

You can check for that, by putting the values into Pythagoras Theorem:
H² = P² + B²
10² = 8² + 6²
100 = 64 + 36
100 = 100
L.H.S = R.H.S

As it obeys Pythagoras theorem, It would be a right-angled triangle only, with two small arms (Base  & Perpendicular) and a long arm, opposite to perpendicular (Hypotenuse)!!!

Hope it helped.

Any time you see a triangle with 6, 8 and 10 sides, just know it is a right angle triangle.

That is because in a right angled triangle, the sum of the squares of the two smaller sides = square of the greatest side. This law is called the Pythagoras theorem.

Let us check.

6² + 8²

36 + 64

100

Square of the greatest side:  10² = 100

So therefore : 6² + 8² = 10²

So it is a right angled