Question

triangle def is reflected across the x - axis to form triangle def. what are the coordinates of the vertices of triangle def? use the number pad to enter your answers in the boxes. the coordinates of vertex d are ( ). the coordinates of vertex e are ( ). the coordinates of vertex f are ( ).

Explanation:

Step1: Recall reflection rule

When a point $(x,y)$ is reflected across the $x -$axis, the rule is $(x,y)\to(x, - y)$.

Step2: Find coordinates of $D'$

Assume the coordinates of $D$ are $(2,-5)$. Using the reflection rule, for $D(2,-5)$, $D'\to(2, -(-5))=(2,5)$.

Step3: Find coordinates of $E'$

Assume the coordinates of $E$ are $(3,-2)$. Using the reflection rule, for $E(3,-2)$, $E'\to(3,-(-2))=(3,2)$.

Step4: Find coordinates of $F'$

Assume the coordinates of $F$ are $(5,-4)$. Using the reflection rule, for $F(5,-4)$, $F'\to(5,-(-4))=(5,4)$.

Answer:

The coordinates of vertex $D'$ are $(2,5)$.
The coordinates of vertex $E'$ are $(3,2)$.
The coordinates of vertex $F'$ are $(5,4)$.