The sides of a square or rectangle
The answer is 73.5
To make it a lot easier split the shapes into a rectangle and triangle.
The rectangle is a tad easier because the measurements are given here.
5 x 12 = 60 (rectangle area)
To find the triangle find the base then height. The base is 3cm and the height is 9cm (shown above)
9 x 3 = 27
Divide that by 2 because it's a triangle and you get 13.5.
Add those two numbers and voila you have your answer of 73.5.
Answer:
V≈461.81cm³
Step-by-step explanation:

x = 1.50 + y
*40x + 40y = 940
40 (1.50 + y) + 40y = 940
60 + 40y +40y = 940
60 + 80y = 940
80y = 940 - 60
80y = 880
y = 880/80
y = 11
*x - y = 1.50
x - 11 = 1.50
x = 1.50 + 11
x = 12.5
x=DAVID
Y=PETER