Femhörningens vinkelsumma: [url=https://www.geogebra.org/m/pxue2m7h]https://www.geogebra.org/m/pxue2m7h[/url][br]Pythagoras sats: [url=https://www.geogebra.org/m/dBu3hnqx]https://www.geogebra.org/m/dBu3hnqx[/url][br]Randvinkel: [url=https://www.geogebra.org/m/jmabzrty]https://www.geogebra.org/m/jmabzrty[/url][br]Vinklar vid parallella linjer: [url=https://www.geogebra.org/m/ztgesgr6]https://www.geogebra.org/m/ztgesgr6[/url][br]Proof without words (engelsk bok): [url=https://www.geogebra.org/m/jFFERBdd]https://www.geogebra.org/m/jFFERBdd[/url] [br]Quadrilaterals (engelsk bok): [url=https://www.geogebra.org/m/GFwZ5qdf]https://www.geogebra.org/m/GFwZ5qdf[/url][br]Surface area and volume (engelsk bok): [url=https://www.geogebra.org/m/s7TznqSP]https://www.geogebra.org/m/s7TznqSP[/url] [br][br][br]