In ∆ABC, if a = 8.75 centimeters, c = 4.26 centimeters, and m B = 87°, what is the length of b to two decimal places?

Question

In ∆ABC, if a = 8.75 centimeters, c = 4.26 centimeters, and m  B = 87°, what is the length of b to two decimal places?

anonymous · Answer

A)8.92 CM
B)9.41CM
C)9.53CM
D)13.01
E)15.36

itsyacoolgrl · Answer

you will need the law of cosines to solve it

b2=a2+c2−2a×c×cos(B)


just substitute your values

itsyacoolgrl · Answer

Solution:

cosB= (a^2+c^2-b^2)/2ac

b = sqrt(a^2+c^2-2ac*cosB)

= sqrt(8.75^2+4.26^2-2*8.75*4.26*cos87)

=9.53

So b=9.53cm

anonymous · Answer

my teacher hasn't taught us that yet and shes giving us  stuff to do can you walk me through

itsyacoolgrl · Answer

Really? how does she expect you to solve it if you don't know "sohcahtoa"
What grade are you in?

anonymous · Answer

I don't know , ima a sophomore

itsyacoolgrl · Answer

Hmmm, sorry i'm a freshman. Is this for geometry?

anonymous · Answer

yes

itsyacoolgrl · Answer

That's weird :/ I learned sohcahtoa in my freshman year, (I'm going to be a sophomore in the upcoming year). I don't know how to help you but goodluck!