Determining angle side relationships What are the angle measures in trainable ABC?

Answer:
m∠A=90°, m∠B=60°, m∠C=30°
Step-by-step explanation:
step 1
Verify if the triangle ABC is a right triangle
Applying the Pythagoras theorem
[tex]12^{2}=6^{2}+(6\sqrt{3})^{2}[/tex]
[tex]144=144[/tex] ----> is true
therefore
Is a right triangle
m∠A=90°
Find the measure of angle C
sin(C)=AB/BC
substitute
sin(C)=6/12=1/2
so
m∠C=30°
Find the measure of angle B
we know that
m∠C+m∠B=90°------> by complementary angles
so
m∠B=90°-30°=60°