Answer:
The correct answer is option D
Step-by-step explanation:
In option A: angle1 + angle2 + angle3 is not equal to 90°
In option B: angle1 + angle2 + angle3 = 180 but it is easier to find angle1 with option D
In option C: angle1 - angle2 is not equal to angle3
In option D: angle1 + angle2= angle3 [by using exterior angle property]
I hope you understood my answer well :)
