Question

Сделайте номер 9.3 пж

Answer 1

BE=BD/2
BE=14/2=7cm

β=180-α
β=180-120=60

∠Y=β/2
∠Y=60/2=30

sinY=BF/BE
BF=sinY*BE
BF=sin30 * 7 = 1/2 *7 = 3.5cm