exo de maths difficile 3 eme

bonsoir

ACDA = AC + CD + DA

DA² = 1.4 ² + 1.05 ²
DA² = 3.0625

DA = V3.0625

DA = 1.75 km 

donc acda = 1.4 + 1.05 + 1.75 = 4.2 km 

AE'/AE = AF'/AF = E'F'/EF

0.5/1.3 = 0.4/EF

Ef = (0.3*0.4)/0.5 = 0.24 

EF = 0.24 km

parcours aefa = 1.3 + 0.24 + 1.6 = 3.14 km