Răspuns:
Explicație pas cu pas:
ΔCBD =drepunghic
CD²=BD²+BC²=4²+3²=16+9 =25
CD =√25 =5 cm
construim BE si DF ⊥ CD
BE =C×C/ip =4×3/5= 12/5 cm
CE²=BC²-BE²=3²-(12/5)²=9-144/25 =225/25-144/25=81/25=9/5 cm
CE=DF=9/5cm
AB=5 -(2×9/5)=5-18/5=25/5-18/5 =7/5 cm (a)
