Respuesta :

Answer:

theta  = 180 -(A +B)

Step-by-step explanation:

The sum of the angles of a triangle is 180

theta + A + B = 180

solve for theta

Subtract ( A + B) from each side

theta +A+B -(A +B) = 180 -(A +B)

theta  = 180 -(A +B)