4./3
find the sine and the cosine of 309,

sin(309) = 0.902 cos(309) = 0.432

Explanation:

We can find the nearest possible value and can approximate them for our answer.

now, nearest value possible can be considered 307 in case of 309 angle as 307 can be written as 360-53

and we know the values of sin(360) , cos (360) and sin(53) , cos (53) and the formula to be used is

sin(A-B) = sinAcosB - cosAsinB and

cos(A-B) = cosAcosB + sinAsinB.

Taking A as 360 and B as 53

and substituting values, we get ,

sin(A-B) = (3/5)*0.9 - 1*4/5 = approx 0.902 for sin(309) and

cos(A-B) = 1*3/5 + 4/5*0.9 = approx 0.432 for cos(309).

step-by-step explanation:

answer: the angel abc is 30°,and the abc is a triangle where the angel bac is 90°

so ac is the half of 24=12ft,and from the pythagorean theorem we find ba

ba=√bc^2-ac^2=√576-144=√432=12√3ft

so bac is 12+12√3=12(1+√3)ft