Answer:9090
it is simple you just need to multiply by 2
It is asking you to convert them to different units of measurements.
Let the height of the rectangle = h
2b + 2h = 100
2(38) + 2h = 100
2h = 100 - 76
h = 12mm
area of rectangle = base x height
= 38 x 12
= 456mm²