First of all this is a very poor question, and you should question it a bit. What are these figures? Are they regular? (first 2). Is the last one a parallelogram. I'm going to assume that the yellow one is a rectangle and the middle one is a pentagon and the last one is a parallelogram.
Yellow
A has 4 right angles (That's the property of a rectangle).
Green
B has 5 angles that are equal to 108 degrees. If you draw a 2 lines from any vertex you get 3 triangles. The size of the interior angles totals 3 triangles * 180 degrees = 540 degrees.
540/3 = 108.
Each angle in the interior is 108 degrees.
B has 5 angles all equal 108 degrees. All 5 are obtuse.
Red
Just by sight and assumption C has 2 obtuse angles, and 2 acute angles.