Rectangular isn't a map projection, and here's how cylindrical, conic, and planar projections shape our maps

Mapping the world isn’t just about drawing lines on a page. It’s a conversation between geometry and reality, a little dance that helps sailors, pilots, and land navigators get from point A to point B with confidence. If you’re part of LMHS NJROTC’s academic crew, you’ve likely caught yourself thinking about maps in more than one way: how a shape on a globe becomes a flat picture, and why that picture sometimes looks a little wonky near the edges. Here’s a friendly guide to map projections that keeps things clear, practical, and a touch interesting.

Let’s start with the basics: what is a map projection, exactly?

Put simply, a map projection is a method for translating the curved surface of the Earth onto a flat surface. Every projection makes a trade-off. You can preserve angles (so compass directions stay true) but wind up distorting sizes. Or you can keep areas reasonably accurate and let distances or shapes slip a bit. The old cartographers didn’t have the luxury of a single perfect map; they had to choose the trade-off that mattered most for the job at hand—navigation, land surveying, weather mapping, or education.

Three main families you’ll hear about (plus a common misconception)

When you study maps, you’ll often hear about three primary projection approaches:

• Cylindrical projections: The Earth is wrapped around a cylinder, then laid flat. These are great for preserving shapes and angles in many parts of the world, which is why they show up in navigational tools and many world maps. A famous example is the Mercator projection, which helps sailors plot courses by lines that stay straight. The catch? Areas get wildly distorted toward the poles—the Greenland-and-Antarctica scale inflation you’ve probably seen.

• Conic projections: The Earth is projected onto a cone held over it. These work well for mid-latitude regions (think the continental United States or Europe). They often strike a good balance between keeping shapes recognizable and keeping areas from getting completely out of whack. They’re common in regional maps where you want reliable landform relationships without extreme distortion.

• Planar (often called azimuthal) projections: The Earth is projected onto a flat plane from a single viewpoint—imagine a light bulb shining onto a map. Distances and directions from the center can be very accurate, which makes this kind useful for mapping polar regions or showing how far two places are from a central point.

One word that isn’t a projection type—and why it matters

So, what about “rectangular”? If you’ve ever described a map as rectangular in shape, you’ve touched on the layout, not the projection method itself. Rectangular is a description of the map’s appearance, not a formal technique for wrapping the globe. In cartography, you might encounter a rectangular-looking world map produced by a cylindrical projection, such as the Plate Carrée (also called the equirectangular projection). That map appears rectangular because the cylinder’s unrolling creates a grid that stretches the horizontal lines evenly across the page. But the act of projecting the Earth onto a cylinder is what defines the projection, not the final rectangle shape you see on the wall.

That distinction isn’t just nitpicking. It helps you read maps with a sharper eye. If you see a rectangular map, you can ask: is this a Plate Carrée (a type of cylindrical projection) or is the rectangle just the page layout? The answer changes what distortions you should expect and how you interpret distances and areas.

A closer look at each type (in plain language)

• Cylindrical: Imagine rolling a globe into a cylinder and then flattening it. Shapes can stay pretty true along the equator, which is handy for navigation since courses look like straight lines. But up near the poles, everything balloons. If you’ve ever noticed that Greenland looks enormous on a typical world map, you’ve seen this distortion in action.

• Conic: Picture a cone perched over the globe. Lines of latitude map to circles on that cone, and the result often keeps landmasses looking more natural in their sizes. Great for country-level or regional maps, where you want a nice mix of outline accuracy and reasonable area representation.

• Planar (azimuthal): A single point on the Earth becomes the center of your map. Distances and directions from the center can be quite reliable, which makes this a handy choice for radio range calculations, spacial planning, or exploring polar zones.

Why this matters for someone in NJROTC

If you’ve spent any time with navigation or map-reading in a naval context, you know how important it is to understand what a map is good for. A navy map in a cylindrical projection will give you excellent directional cues along straight routes, but you’d want to be cautious about distance measurements at high latitudes. A conic projection might serve you well for planning operations across a country or region where you need balanced shape and area. A planar projection could be perfect when you’re plotting routes from a central observation point and you need precise distances from that center.

It’s tempting to want a single map that does everything perfectly. Real life isn’t generous with absolutes, though. The trick is picking the right tool for the mission at hand, and that starts with recognizing which projection family a map uses. If you’re evaluating a chart for a task, ask yourself a few quick questions:

• What is the geographic focus? Global, regional, or local?

• Do I need accurate shapes, accurate areas, or accurate distances from a center point?

• Will distortion near edges matter for this assignment or task?

A small classroom-friendly analogy

Think of map projections like lenses for a camera. A wide-angle lens captures more of the scene (good for landscapes), but some details might look a little compressed or stretched at the edges. A telephoto lens zooms in on a small subject with less distortion in that scene, but you miss the big picture. A specialized lens, like a fisheye, distorts aggressively but can reveal patterns you wouldn’t see otherwise. The projection you choose works similarly: you pick the lens that reveals what you need without losing sight of the limitations.

A practical nudge for your map literacy

• If you’re ever unsure whether a map is truly reliable for measuring area, locate a region you know well and compare the land-to-water ratios with a globe. If the numbers look off, the projection’s distortions are doing their part.

• If you’re curious about the physics of navigation, check out how compasses and course plotting behave on a cylindrical map vs. a planar one. You’ll notice the straight-line courses on a Mercator map are great for direction but not for true distance over larger areas.

• Don’t worry about memorizing every detail of every projection. The goal is to be comfortable recognizing the three big families and knowing when each one shines.

A few more practical notes you can tuck away

• Rectangular maps aren’t a separate category of projection; they’re often the end result you see from cylindrical projections. So when someone says a map looks rectangular, it’s a clue about layout rather than a new projection method.

• In digital cartography and geographic information systems (GIS), you’ll encounter dozens of projection options. The same geographic dataset can look quite different depending on the projection chosen. That’s not a flaw; it’s a feature that helps tailored visualization and analysis.

• For learning and memory, place names and features often stay readable in multiple projections. It’s the shapes and relative areas that shift most noticeably.

Let’s tie it back to the core idea

The quick takeaway is simple: Cylinder, cone, and plane are recognized ways to wrap the Earth onto a flat surface, each with its own strengths and distortions. Rectangular, while describing a map’s shape, isn’t a distinct projection method. So, in a multiple-choice moment, the answer is Rectangular—not because maps can’t look rectangular, but because “rectangular” isn’t how professionals classify the projection techniques themselves.

A nod to curiosity and continued exploration

Maps are more than tools; they’re stories about space and scale. They invite us to ask why a coastline looks smoother on one map and rougher on another, or why the same country can feel so small in one version and surprisingly large in another. If you’re drawn to that kind of puzzle, you’re with the right crew. The world is a big, layered place, and map projections are the clever tricks people use to make sense of it.

A closing thought you can carry forward

When you’re next eyeing a map, try labeling the three projection families in your own notes and jot a quick one-liner on what each is best for. It’s a tiny habit, but it builds sharper intuition. And if you ever want to talk about a map you found online, I’m happy to break down what projection it uses and what that means for what you’re seeing. Maps are meant to be read, not just looked at, and the more you understand their language, the closer you get to reading the world with confidence.

If you’re hunting for more clarity on geographic ideas, you’ll find this kind of explanation pops up again and again—whether you’re plotting a field exercise, looking at aerial photos, or just appreciating how a globe becomes a flat page. The key is to remember that a map’s shape isn’t a verdict on its truth; it’s a choice that helps you get the job done. And with that mindset, you’ll move through geographic challenges with a steady compass and a curious eye.