Question

Calculate the side lengths a and b to two decimal places.

Answer 1

Do you know the Law of Sines?

Answer 2

a/sinA=b/sinB=c/sinC

Answer 3

@phi

Answer 4

yes, though you only "use" two out of the three when you solve a problem.

Your first step should be to find the 3rd angle C (opposite the know side of length 9.3)
so you can use
9.3/sin C = a/sin(64) (for example

Answer 5

do i cross multiply

Answer 6

first, did you find the 3rd angle ? (using the sum of the 3 angles must be 180º)

Answer 7

you need angle C. use
C+64+85= 180

can you find C ?

Answer 8

i got 31

Answer 9

ok, now you can use the Law of Sines
\[ \frac{9.3}{\sin 31}= \frac{a}{\sin 64} \]
to solve, I would multiply both sides by sin 64
like this:
\[ \frac{9.3}{\sin 31}\cdot \sin 64= \frac{a}{\cancel{\sin 64}}\cdot \cancel{\sin 64} \]

Answer 10

on the right side sin64/sin64 = 1 (cancels out)
and you have a = 9.3 * sin 64 / sin 31

Answer 11

i dont know how to calculate sin on my calculator

Answer 12

do you have a button that says sin ?

Answer 13

yes

Answer 14

what do you get when you type
sin 90 =

Answer 15

.8939

Answer 16

your calculator is in radian mode.
use the "mode" button and see if you can find how to switch to degree mode.

Answer 17

what model is your calculator?

Answer 18

ok i got 1
for sin of 90

Answer 19

ok, now you can solve for a

Answer 20

does a = 16.22

Answer 21

show more decimals

Answer 22

16.22944

Answer 23

to answer
Calculate the side lengths a and b to two decimal places.

you look at the *third* decimal place. if 5 or bigger, you round up the 2nd decimal place.
otherwise, leave the 2nd decimal place as is.

Answer 24

so a= 16.23

Answer 25

yes.

can you set up the Law of Sines for finding side b? (use side 9.3 and angle 31º again)

Answer 26

so b=17.99

Answer 27

yes