Koi are pond fish and grow to over 24 inches or so when adult. It is unlikely they will breed for you in a small aquarium. (It is also unlikely they will live long in a small (under 75 gallons) aquarium)
Koi Anunta is 5' 4 1/2".
4 ft 4 in
It seems someone somewhere is preying upon the gullibillity and ignorance of the fish buying public and selling something that is not a Koi as a Koi. (Officially/Taxonomicaly there is no such thing as a Koi Swordfish). Koi (Cyprinus carpio) is not a description it is a species. They are cold water egg layers that can grow to around 4 or 5 feet long. Koi are members of the goldfish family. Guppies (Poecilia reticulata) are tropical livebearing fish and grow to a maximum of 2 inches. These two species obviously can not cross breed. It is possible that (In America) the common Swordtail Guppy is now being promoted/sold as a Koi Swordtail. If this is the case then yes all of the many different colour types and fin types of guppy (Poecilia reticulata) can and will readily breed with one another because they are the same species.
4
.4 of an inch as a fraction is 4/10 or 2/5 of an inch in its simplest form
The standard PVC conduit dimensions used in electrical installations are typically 1/2 inch, 3/4 inch, 1 inch, 1 1/4 inch, 1 1/2 inch, 2 inch, 2 1/2 inch, 3 inch, 3 1/2 inch, 4 inch, and larger. These sizes refer to the diameter of the conduit.
The area of a 2 by 2 inch square is 4 square inches. The formula is length times width. Like 4 inch by 6 inch. 4 times 6 equals 24 square inches
half an inch
A common guideline for stocking koi fish in a tank is to allocate about 10 gallons of water per inch of fish. Therefore, in a 40-gallon tank, you could theoretically keep around 4 inches of koi fish. However, it's important to consider that koi can grow quite large and produce significant waste, so it's often best to keep fewer fish to maintain water quality and ensure their well-being. Additionally, koi are typically better suited for larger outdoor ponds rather than small tanks.
1/2 inch for 1/2 inch pipe.
4 x 4 x 2 = 32 cubic inches.
I assume you mean a 4 x 2 square tube that is loaded in the direction of the 4 inch dimension; then it is stronger than a 4 inch channel with flange width of 2 inches loaded in the direction of the 4 inch dimension, because the square tube has more inertia