Question

С

a
Find all the missing elements:
B
A = 40°
a = 8
А
b = 7
b
B = [?]° C = [ ]° c = [ ]
Round to the nearest tenth.
C С

Answer 1

B=34.2

C=105.8

c=12.0

Explanation:

find B using the sine rule

(sin40÷8)=(sinB÷7)

rearrange

sin B= (sin40x7)÷8

sin B=0.562

make sure to use your calculator

then press shift sin to find B

B= 34.2°

to the nearest tenth means to 1 decimal place

sum of angles in a triangle is 180

so 180-(40+34.2)=105.8°=C

use sine rule again to find c

(sin105.8÷c)=(sin40÷8)

rearrange

c= (sin 105.8x8)÷sin40

c=12.0