Question 1114153
If B is the base for triangle XYZ
then  {{{(1/2)B*15=areaOfXYZ}}}.


If b is base for triangle QRS
then  {{{(1/2)b*8=145}}} as given its area.
-
{{{b*4=145}}}
{{{b=145/4}}}
{{{b=36&1/4}}}


Assuming these are similar triangles, {{{B=(15/8)b}}}
{{{B=(15/8)(145/4)}}}
{{{B=67.96875}}}


Area of triangle XYZ:
{{{(1/2)*67.96875*15}}}
{{{highlight_green(509.76563)}}}
or about 509.77.


NOT the only way to solve.  There is a linear-to-area property for plane figures.