Respuesta :

Use the Sine Rule:-

12 / sin 23 = 15 / sin B

sin B = 15 sin 23 / 12

m < B = 29.236 degrees

so m < C = 180 - 23 - 29.236 = 127.76 degrees

Using Sine Rule again:-

12 / sin 23 = c / sin 127.76

c = 12 * sin 127.76 / sin 23

= 24.5 to nearest tenth