Prove that the areas of all three triangles in the picture in the right

Prove that the areas of all three triangles in the picture in the right OJ u,neup s! 0) D •go apys OLD JO Buyppe Kq '(10) popumxa s! öliuegl oms acp 'mopq 111 •tenbo oue SOP!S o) Oliue ueJO -A uo Kue s.retn0!puod.10d aquo stpfit101 jetp a,t0Jd •oßueyl apqm eare ot0JO e 0) lenbo ue uo un13!d u! salfiuepl IPJO span Jetp OAO.Id u! ILI!0d alp ump pue apys OJ!soddo OLßJ0 ILI!0d P!Lu pau10( s! aliue!-n e JO xauaA dm •mopq a.1nJ0!d atp ul (s)