Răspuns:
Explicație pas cu pas:
EP ⊥ DF ; EP = ?
--------------
a) Aria Δ DEF = 42 cm² ; DF = 12 cm
Aria = (DF·EP)/2 = 42 cm² =>
DF·EP = 42·2 = 84 => EP = 84/DF => EP = 84/12 => EP = 7 cm
---------------------------
b) Aria Δ DEF = 48 cm² ; DF = 16 cm
Aria = (DF·EP)/2 = 48 cm² =>
DF·EP = 48·2 = 96 => EP = 96/DF => EP = 96/16 => EP = 6 cm