Classify the triangle with sides measuring 11 cm, 5 cm,

Question

and 10 cm.

equilateral

isosceles

scalene

none of the above

Answer 1

You only have 3 choices:
equilateral: all sides would have to be equal. Are they?
isoscelse: two of the sides would have to be equal. Are they?
scalene: all sides are different. Are they?

All you had to know was the names of these terms.

Answer 2

Obviously you don't know the meanings of all of these terms.

http://www.mathwarehouse.com/geometry/triangles/triangle-types.php