Create a Rectangle with Two Rounded Corners
Many of my students insist that it’s not possible to create a rectangle with two square corners and two rounded corners in InDesign. But it is! Simply draw a rectangle and select it with the Selection tool. Hold your Shift + Option keys (Shift + Alt on PC) and Click-Drag the rectangle horizontally to create a copy that’s overlapping the original. With the copied rectangle still selected, go to Object > Corner Effects, choose Rounded for Effect, specify a Size and click OK. Marquee across both Rectangles to select them and then in your Pathfinder palette (Window > Object & Layout > Pathfinder) click the Add Pathfinder button (far left) to combine the two rectangles. You’ll end up with an impossible rectangle with two rounded corners.
Tip provided by Jeff Witchel, Certified Adobe® Training Provider.