Answer:
25
Step-by-step explanation:
The sum of the three angles of a triangle are 180 degrees
We have
(n+40) + 90 + n = 180
Combine like terms
2n +130 = 180
Subtract 130 from each side
2n +130-130 = 180-130
2n = 50
Divide by 2
2n/2 = 50/2
n = 25
