Answer:
[tex]A=19.2^o\\B=57.6^o\\C=103.2^o[/tex]
Step-by-step explanation:
we know that
The sum of the interior angles in any triangle must be equal to 180 degrees
so
[tex]A+B+C=180[/tex] ----> equation a
[tex]B=3A[/tex] ----> equation b
[tex]C=6A-12[/tex] ----> equation c
Solve the system by substitution
Substitute equation b and equation c in equation a
[tex]A+3A+6A-12=180[/tex]
Solve for A
[tex]10A=180+12\\10A=192\\A=19.2^o[/tex]
Find the measure of angle B
[tex]B=3(19.2^o)=57.6^o[/tex]
Find the measure of angle C
[tex]C=6(19.2)^o-12=103.2^o[/tex]