Answer:
D. 4
Explanation:
The 55 degree angle can be either a base angle or the apex angle.
The 6 inch length can be either the length of the base or the length of each leg.
There are therefore 4 possible triangles:
1. 55 degree base angle and 6 inch leg length
2. 55 degree base angle and 6 inch base length
3. 55 degree apex angle and 6 inch leg length
4. 55 degree base angle and 6 inch base length
(2 with only 1 angle of 55 degrees (1 with the equal sides of 6 inches each, 1 with the unequal side of 6 inches)
2 with 2 angles of 55 degrees (1 with the equal sides of 6 inches each, 1 with the unequal side of 6 inches).)