Question

If the ratio of the length of segment AC to the length of segment CB is 3:1, what is the y-coordinate of point C?

Answer 1

Answer:

The coordinates of point C are (8,8.5)

Step-by-step explanation:

The picture of the question in the attached figure

Let

$(C_x,C_y)$ ----> coordinates of point C

we have that

The horizontal distance AB is equal to

$AB_x=10-2=8\ units$

The vertical distance AB is equal to

$AB_y=10-4=6\ units$

Find the horizontal coordinate of point C

we know that

$\frac{AC}{CB}=\frac{3}{1}$

so

$\frac{AC_x}{CB_x}=\frac{3}{1}$

$AC_x=3CB_x$----> equation A

$AC_x+CB_x=8$ ----> equation B

substitute equation A in equation B

$3CB_x+CB_x=8$

$4CB_x=8\\CB_x=2$

$AC_x=3(2)=6$

so

The x-coordinate of point C is equal to the x-coordinate of point A plus the horizontal distance between the point A and point C

$C_x=A_x+AC_x=2+6=8$

Find the vertical coordinate of point C

we know that

$\frac{AC}{CB}=\frac{3}{1}$

so

$\frac{AC_y}{CB_y}=\frac{3}{1}$

$AC_y=3CB_y$----> equation A

$AC_y+CB_y=6$ ----> equation B

substitute equation A in equation B

$3CB_y+CB_y=6$

$4CB_y=6\\CB_y=1.5$

$AC_y=3(1.5)=4.5$

so

The y-coordinate of point C is equal to the y-coordinate of point A plus the vertical distance between the point A and point C

$C_y=A_y+AC_y=4+4.5=8.5$

therefore

The coordinates of point C are (8,8.5)