lakes
because they follow rivers
Some borders are made by natural features, such as rivers. Other times, there might be a straight line determined by geographical latitude or longitude.
Straight borders are often a result of surveying methods used during land divisions, while crooked borders can be influenced by natural geographic features or historical boundaries established through treaties or agreements. Additionally, straight borders may also reflect efforts to simplify administration and governance in regions with more uniform characteristics.
land surveyors as directed by political agreements
if you mean which countries have borders that are entirely made up of straight lines like say the state of Utah then none but if you mean which countries have borders that include at least some lines that are entirely or perfectly straight then probably all or nearly all A few examples like Papua New Guinea and Egypt do however come close to entirely straight borders Land borders are defined by border markers. These are placed by mutual agreement by the two countries and mark out the border. They can be anything from a few tens of metres apart to a few Km apart. Normally they are within sight of each other. The border is deemed to run in a straight line from on border marker to another. Most borders are therefore a large number of relatively short straight lines, and most borders are defined by straight lines. This does not apply to borders which run along rivers or lakes. in this case the border is normally the centre of the river, which is not a straight line. Note a line of latitude (xx °N or yy °S) is not a straight line.
Some national borders follow lines of longitude. For example, the 38th Parallel is the DMZ which demarcates the Republic of Korea (South) from the DPRK (North).
Examples of types of borders include natural borders (such as rivers or mountain ranges), artificial borders (such as walls or fences), and political borders (such as agreed-upon boundaries between countries). Borders can also be defined by treaties, historical agreements, or physical landmarks.
Rivers, Oceans, Seas, and Mountains.
there are over 100 rivers, the best way to answer that question is to search it up bevause there are so much rivers
Yes. That is to say, some are straight; the border between Canada and the United States is, for 2/3 of its length, straighter than an arrow for about 2,000 miles. The world's most famous surveyors, Mason and Dixon, drew the border between Maryland and Pennsylvania as straight as 1760's technology could achieve. The border between Florida and Georgia is mostly straight. Much of the border between California and Nevada is two straight lines. And the border between Pennsylvania and Delaware includes a quarter of a perfect circle. But most borders follow geographic features, which are wiggly, crooked, bent, and twisty. They follow rivers, mountains, and coastlines.
Some examples of natural borders separating countries include rivers (such as the Rio Grande between the US and Mexico), mountain ranges (like the Andes between Chile and Argentina), and bodies of water (like the English Channel between the UK and France). Oceans, deserts, and forests can also act as natural borders.
Sea fish don't live in rivers because rivers don't have coral or any sea plants. The sea plants are vital for some fish. That and some of the sea fish are to big for rivers.