Question

Un triunghi ABC,m(A)=90* ,cu AD perpendicular pe BC ,Aparține (BC)
BD?
CD?
AD?
BC?
AB=15
AC=20

Answer 1

Răspuns:

BD=9 cm

CD=16 cm

AD=12 cm

BC=25 cm

Explicație pas cu pas:

1. BD:

ip² = c1²+c2²

BC²=AB²+ AC²

BC²=15²+ 20²

BC²=225+400

BC²=625

BC=25 cm

2. BD

CTC: AB²= BD×BC

15²= BD×25

225= BD×25

BD=225÷25

BD=9 cm

3. DC= BC – BD

DC= 25 – 9

DC= 16 cm

4. tr. ABC-dr , m(<BAC)= 90°

=> CTÎ : AD²= BD×DC

AD²= 9×16

AD²= 144

AD= 12 cm