Question

Triangle sum theory; solve for x.

Answer 1

49 degrees.

Explanation:

all triangles will have angles add up to 180, 89 + 42 = 131

180 - 131 = 49

Answer 2

`\sf\\x+89^o+42^o=180^o\ \ \ [\textsf{Sum of interior angles of a triangle is }180^o.]\\or,\ x+131^o=180^o\\or,\ x=49^o`