How do I draw a curve confined by a triangle?

I don’t know how to describe this better, so I’ll just draw it:


(It took my 10 minutes to figure out how to draw this in inkscape)

What I’m trying to do is draw this curve, but ensure that curve is completely constrained by the triangle. When I try to use the 2-point arc tool, anything by the slightest curve extends outside the triangle.

(I’m using Sketchup Make 2017)

Bezier curve is totally the way to go here. But I got to thinking about how one might achieve this in SketchUp Free or without extensions. It is kludgy with much less control but, using scale tool to skew an arc and using only a section of it might get you something close.

You also may want to try the scale tool on an isosceles triangle with a tangent ‘2 Point Arc’:

added: Little correction, the popup at the grid should read "Green Scale about Opposite Point"
(my mistake due to the way the screen capture had to be taken, involving the use of [Ctrl])


You can always just use the 2 point arc twice.
But a lot depends on exactly what curve you want.
2point arc