Respuesta :

Answer:

[B] 12°

Step-by-step explanation:

Given:

Triangle ABC is a right triangle, and m∠ C is 78°.

Solution:

Knowing that Triangle = 180 degree

Square in a right angle = 90° angle.

Thus,

78+90 =168

180-168 is 12

Hence, the answer is [B] 12 degree

Kavinsky