Question

Which line is a line of symmetry of ΔABC?

A) line b
B) line a
C) line c
D) line d

Answer 1

Line of symmetry cuts the intended figure/graph/line etc. into 2, where the 2 parts reflect each other exactly about the line of symmetry itself.

Line a is the answer, since line a cuts triangle ABC into 2 triangles, which reflect each other exactly about line a. Triangle ABdot and triangle CBdot are congruent and reflect each other about line a. ("dot" refers to the point that has the right-angle sign in the figure)

Hope this helps! :)

Answer 2

A)line a

Explanation:

Line of symmetry:It is defined the line which is passing through the center of an figure and divides the figure into two equal halves.

In other words we can say that

Line of symmetry: When a figure reflect over a line and the figure remains same .Then , the figure has reflection of symmetry or line symmetry.The line that reflects over is called line of symmetry.

The line of symmetry divides the figure into two mirror image halves.

From given figure, we can see that

line a is passing through the center of the triangle ABC and divides the triangle ABC into two equal halves.

But , line b ,line c and line d do not divide the triangle ABC into two equal halves .Hence, these lines are not line of symmetry of triangle ABC.

Hence, the line of symmetry of triangle ABC is line a.