Question

select the correct answer.
when using a reflective device such as a mir to bisect angle abc, where should the reflective device be placed?
a. place one end of the reflective device on the vertex a and swing the other end until you can see the reflected line - segment ab coincide with line segment ac
b. place the reflective device along line segment ac
c. place the reflective device along line segment ab
d. place one end of the reflective device on the vertex b and swing the other end until you can see the reflected line segment bc coincide with line segment ab

Explanation:

To bisect an angle using a reflective device, we need to use the property of reflection to make the two - sides of the angle coincide. The vertex of the angle is the key point. We place one end of the reflective device on the vertex of the angle and adjust it until the reflected part of one side of the angle coincides with the other side. For angle $\angle ABC$, the vertex is $B$.

Answer:

D. Place one end of the reflective device on the vertex B and swing the other end until you can see the reflected line segment BC coincide with line segment AB