Answer: a=5
b=4
c=5
d=20
Step-by-step explanation: Looking at the bottom picture, we can see that the height of one rectangle is 5 cm. Therefore, a will be 5 cm. This will be the same for c, which will be 5 cm. We can see that b is on the bottom side of the square, and 4 cm is on the bottom of the square (top picture). Therefore, b is 4cm. The d is the longest, and will be 20 cm.