If the above image is the supposed image for this problem, then,
B. Angle A, Angle B, and Angle C, form a straight angle.
A straight angle is 180°. C A B found in the middle of the picture forms the 180° straight angle.
Right angle is an angle which is equivalent to 90°
Acute angle is an angle which has less than 90°
As I can observe, the three triangles have two equal sides and two equal angles. These triangles are identified as isosceles triangles.
