Use the Style Spline
tool to sketch single-span Bézier curves. These curves let you create smooth and robust surfaces, and are available in 2D and 3D sketches.
The style spline consists of only one span. You shape its curvature by selecting and dragging control vertex points. Sketch entities connect the control vertices which form the control polygon of the curve.

With style splines, you can easily control the degree and continuity of the curves. You can inference style splines for tangency or equal curvature. You can constrain the points and dimension the curves' sides. These curves also support mirroring and self-symmetry.

You can access the Style Spline tool from Style Spline
(Sketch toolbar) or .