Answer:
The remaining interior angles of this triangle are 140º and 10º
Explanation:
The sum of the interior angles of a triangle is always 180º.
A triangle has 3 angles. In this problem, we have one of them, that i am going to call A1 = 30º.
The sum of a interior angle with it's respective exterior angle is also always 180º.
We have that one of the exterior angles is equal to 40°. So it's respective interior angle is
40º + A2 = 180º
A2 = 180º - 40º
A2 = 140º
Now we have two interior angles, and we know that the sum of the 3 interior angles is 180º. So:
A1 + A2 + A3 = 180º
A3 = 180º - A1 - A2
A3 = 180º - 30º - 140º
A3 = 180º - 170º
A3 = 10º