Answer:
d. 6.4
y = 62°
Step-by-step explanation:
Using Trigonometric ratio,
sin45° = 4/ AC
AC = 4/sin45° = 4 ÷ 1/√2
AC = 4√2
Using Pythagoras' Theorem,
AD^2 = AC^2 + CD^2
AD^2 = (4√2)^2 + 3^2
= 16×2 + 9
= 32 + 9
= 41
Take square roots of both sides
AD = √41 = 6.4
cos y = 3/√41 = 0.4685
y = arccos(0.4685)
y = 62.06°
y = 62°