Beispiel aus einer GeoGebra-Aufgabe: "Zwei Kreise mit gleichem Radius r sollen so zum Schnitt gebracht werden, dass..."
Deutsch: http://www.didaktik.mathematik.uni-wuerzburg.de/zula/extremw...

Similar tutorial in English: "...6 Next, we have to intersect the circles. To intersect the two circles, click the inverted triangle on the New Point tool, select Intersect Two Objects,..."
http://wiki.geogebra.org/en/Tutorial:EquilateralTriangle

And in the context of turbomachinery:
"Usually it is not practical to obtain blade surface coordinates precisely on the end-wall contours due to the presence of a fillet radius or a clearance gap. That is not a major problem since program RIGPAC needs only the line-element definition so long as the actual end-wall contour is known. Hence, blades defined by the surface coordinates should also be supplemented by (z, r) coordinates for the actual contours of the end-walls. Those coordinates simply define the contours and need not correspond to points where the blade surface coordinates are supplied. Program RIGPAC can impose those definitions of the end-wall contours and extend the blade surface line elements to intersect them."
http://turbo-aero.com/Documents/RIGPAC.pdf