Set up two equations
T = how tall
W = how wide.
T = W + 25 is the first equation
5
×
{
2
(
T
+
10
)
}
+
5
×
(
2
×
W
)
=
1350
This equation is the total height adding 5 for the top border and 5 for the bottom border. Then multiplying the total height by the width of the border 5, time 2 because there are two sides that are tall Then adding 5 times two widths.