
Answer:
2a(a+2b) square metres
Step-by-step explanation:
surface area of a box = 2(lw+wh+lh)
l is the length = a metres
w is the width = a mtres
h is the height = b metres
Substitute into the formula
surface area of a box = 2(a*a+ab+ab)
surface area of a box = 2(a² + 2ab)
surface area of a box = 2a(a+2b) square metres
This give sthe surface area of the box