Next you’ll make a copy of the original triangle and make a mountain shape with a rounded
corner top.
Click the darker gray triangle to select it. Option-drag (macOS) or Alt-drag (Windows) the
triangle into the lower-left corner of the artboard to make a copy. Release the mouse button
and then the key.
Click More Options ( ) in the Transform section of the Properties panel to the right to show
more options. To return the triangle to an equal-sided polygon, click the Make Sides Equal
button.