science

Quadrangle (geography)

Quadrangle (geography) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Quadrangle (geography) rather than just read about it. In short: A quadrangle (or quad) is a region of the Earth's surface bounded by two parallels (circles of constant latitude) and two meridians (lines of constant longitude). The term is especially associated with topographic maps produced by the United States Geological Survey (USGS) of quadrangles covering the United States.

Key takeaways

Quadrangle (geography) belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Quadrangle (geography) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Quadrangle (geography) from memory before moving on to harder problems.

Reference excerpt

A quadrangle (or quad) is a region of the Earth's surface bounded by two parallels (circles of constant latitude) and two meridians (lines of constant longitude). The term is especially associated with topographic maps produced by the United States Geological Survey (USGS) of quadrangles covering the United States. Quadrangle maps are usually named after local physiographic features; for example, "the Ranger Creek, Texas quad". From approximately 1947–1992, the USGS produced the 7.5 minute series, with each map covering an area one-quarter of the older 15-minute quad series, which it replaced. A 7.5 minute quadrangle map covers an area of 49 to 70 square miles (130 to 180 km2). Both map series were produced via photogrammetric analysis of aerial photography using stereoplotters supplemented by field surveys. These maps employ the 1927 North American Datum (NAD27); conversion or a change in settings is necessary when using a GPS which by default employs the WGS84 geodetic datum. Beginning in 2009, the USGS made available digital versions of 7.5 minute quadrangle maps based on GIS data that use the NAD83 datum, which is typically within one meter of WGS84, or within the uncertainty of most GPS coordinate measurements. The USGS also produces quarter quadrangle (QQ) maps of areas 3.75 minutes square. The surfaces of other planets have also been divided into quadrangles by the USGS. Martian quadrangles are also named after local features.

See also GEOREF quadrangle List of quadrangles on Mercury List of quadrangles on Venus List of quadrangles on the Moon List of quadrangles on Mars List of quadrangles on Io List of quadrangles on Ganymede List of quadrangles on Callisto Quadrilateral

References

Illustrations

Worked examples

Example 1 — a first encounter with Quadrangle (geography)

Start with the simplest possible case. Write down what Quadrangle (geography) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Quadrangle (geography) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Quadrangle (geography) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Quadrangle (geography)

In research: Quadrangle (geography) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Quadrangle (geography) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Quadrangle (geography) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cartography, so understanding it makes those chapters shorter.
In everyday life: Look for Quadrangle (geography) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Quadrangle (geography) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Quadrangle (geography) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Quadrangle (geography) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Quadrangle (geography) in simple terms?

Why does Quadrangle (geography) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Quadrangle (geography)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Quadrangle (geography).