In △abc, m∠a=15°, a=9, and b=12. find c to the nearest tenth.

=20.0

Step-by-step explanation:

We can first find the angle B using the sine rule as follows:

a/Sin A=b/Sin B

9/Sin 15=12/ Sin B

Sin B= (12 Sin 15)/9

=0.345

B=Sin⁻¹ 0.345

=20.18°

We then find C by using the summation of the interior angles of a triangle.

C=180-(20.18+15)

=144.82

Finding the length of c:

a/Sin A= c/ Sin C

9/Sin 15=c/Sin 144.82

c=(9 Sin 144.82)Sin 15

=20.0

answer: a

step-by-step explanation: the answer is a due to the rule of symmetry; that a line of symmetry must divide a figure into 2 pieces that are the exact same, only reflected over a line of symmetry. b and c do not have lines of symmetry and would not divide the figure evenly, thus making the answer a.