To solve for "A" based on the drawing:

1. The radius of curvature (R248) is given as 248 mm.
2. The vertical distance from the bottom of the curve to the top (total height) is 358 mm.
3. The small vertical offset from the top of the drawing to where the curve starts is 12 mm.

To calculate "A", we need to subtract the radius and the offset from the total height:

$A = \text{Total height} - \text{Radius of curvature} - \text{Offset}$ $A = 358 - 248 - 12 = 98 \, \text{mm}$

Thus, $A = 98$ mm.

Let me know if you'd like further details or have any other questions! Here are five related questions:

1. How would you calculate the overall length (OAL) of the shape?
2. What is the relation between dimensions B and C in the diagram?
3. How would the value of A change if the radius of curvature was different?
4. What formula would you use to calculate the arc length of the curve?
5. How do these types of geometric drawings assist in mechanical design?

Tip: Always make sure to clearly identify the segments of a curve to avoid misinterpretation when subtracting measurements.