Answer:
D. 8 1/3
Step-by-step explanation:
solve each traingle
the bottom one:
the line that cut the traingle, made each angle is 90°
10/sin90° = 5/sin?
sin? = 5sin90°/10 = 1/2
the angle is sin^-1 (1/2) = 30° ⇒
10/sin90° = ?/sin60°
? = 10sin60°/sin90° = 5√3 ⇒
12/sin90° = 5√3/sin?
sin? = 5√3 sin90°/12 = 5√3 /12
? ≈46°
180 - (46+90) = 44° ⇒
x/sin44° = 12/sin90°
x = 12sin44°/sin90° = 8.3
x = 8 1/3
