Two lines l and m intersect at O at an angle of 28 degrees. Let A be a point inside the acute angle formed by l and m. Let B and C be the reflections of A over lines l and m, respectively. Find the number of degrees in angle BAC.
Hmmmmm! This is an interesting one...
Here is a picture:
There is a quadrilateral formed in the middle by:
point O, the intersection point of AB and l, point A, and the intersection point of AC and m.
The sum of the interior angles in every quadrilateral = 360º
Look! We know all 3 angles in the quadrilateral except angle BAC.
28º + 90º + m∠BAC + 90º = 360º
m∠BAC = 360º - 90º - 90º - 28º
m∠BAC = 152º