Question 629174
The frame will have a width of 15 cm plus 3 cm on each side = 15 + 3 + 3 = 21 cm. The length will be 20 cm plus 3 cm on each side for a total length of 20 + 3 + 3 = 26 cm. 
The perimeter will be 2 (l + w)
= 2 x (21 + 26)
= 2 x 47
= 94 cm