Question

δabc is reflected about the line y = -x to give δabc with vertices a(-1, 1), b(-2, -1), c(-1, 0). what are the vertices of δabc?
a. a(1, -1), b(-1, -2), c(0, -1)
b. a(-1, 1), b(1, 2), c(0, 1)
c. a(-1, -1), b(-2, -1), c(-1, 0)
d. a(1, 1), b(2, -1), c(1, 0)
e. a(1, 2), b(-1, 1), c(0, 1)

Explanation:

Step1: Recall reflection rule

The rule for reflecting a point $(x,y)$ over the line $y = -x$ is $(x,y)\to(-y,-x)$.

Step2: Reflect point A

Given $A(-1,1)$, applying the rule: $(-1,1)\to(-1,1)$.

Step3: Reflect point B

Given $B(-2,-1)$, applying the rule: $(-2,-1)\to(1,2)$.

Step4: Reflect point C

Given $C(-1,0)$, applying the rule: $(-1,0)\to(0,1)$.

Answer:

C. $A(-1,1), B(1,2), C(0,1)$