Answer:
Line A
Step-by-step explanation:
A line of symmetry is a line that divides a shape into exactly two equal halves.
A triangle is a polygon with three sides and three angles. A scalene triangle has no lines of symmetry, an isosceles triangle has more than one line of symmetry while an equilateral triangle has three lines of symmetry.
From the diagram we can see that line A divides the figure into two equal halves, hence line A is the line of symmetry.
