5π/12 = (5 · 180°) : 12 = 75°
cos 75° = cos ( 45° + 30° )= cos 45° cos 30° - sin 45° sin 30° =
=√2/2 * √3/2 - √2/2 * 1/2 =

=(2.4495 - 1.4142): 4 = 0.258825
Answer:
x = 5
Step-by-step explanation:
using the sine or cosine ratio in the right triangle and the exact value
sin30° =
, then
sin30° =
=
=
( cross- multiply )
2x = 10 ( divide both sides by 2 )
x = 5
5300 and 6000 is the elevation in miles
Answer:
EBC and CBF are supplementary.
EBD=66
Step-by-step explanation:
Since vertical angles are congruent, ABE=CBF
ABE=40-x
40-x + 6x-30=90
5x+10=90
5x=80
x=16
16(6)-30=66