Respuesta :

Answer:

A)

Step-by-step explanation:

A triangle contains 180 degrees when all its corners are added together.

In this case:

180 = 29 + 61 + x

180 = 90 + x

180 - 90 = x

x = 90

90 cause if you add 61 and 29 that equals 90, so add 90+90 and that equals 180