<prompt> Square ABCD ina urefu wa upande 10. Pointi E iko kwenye overlineBC, na eneo la pembetatu ABE ni 40. BE ni nini? asyukubwa4cm;jozi A,B,C,D,E;A0,0;B0,50;C50,50;D50,0;E 30,50;choraA--B;kuchoraB--E;kuchoraE--C;kuchoraC--D;kuchoraD--A;kuchoraA--E;nukta A;nukta B;nukta C;nukta D;nukta E;leboA,A,SW;leboB,B,NW;leboC,C,NE;leboD,D,SE;leboE,E,N;asy  <response>: Eneo la pembetatu ABC ni tfrac12 cdot AB cdot BE. Kwa AB10, tunapata tfrac12 cdot 10 cdot BE 40, au 5 cdot BE 40. Hivyo, BE tfrac405 8. 