Answer:
A = 1 1/4''
Explanation:
The width of the manufactured part is 2 inches (it's shown on the left side). The addition of the radius at the bottom (1/2 inches), the separation of this radius from the edge (1/4 inches) and the measurement of dimension A is equal to the width, then:
1/2'' + 1/4'' + A = 2''
A = 2'' - 1/2'' - 1/4''
A = 1 1/4''