Answer:
C. Right, D. Obtuse and F. Scalene
Explanation:
A Right triangle will have a 90* angle,
An Obtuse triangle will have a right angle and 2 acute angles.
A Scalene triangle will have 3 different angles.
As for what it is not,
Isosceles triangle will have two equal sides.
Acute triangle will have all three angles less than 90 degrees.
and
An Equilateral Triangle will have 3 sides that are all the same length.
Hope this helps! :)