Have you ever created a map?

Kevin and his pen pal Charlotte are both creating maps of their neighborhoods to show each other what it looks like where they live. Kevin has decided to name the most important things on his map. He has decided to include his house, his school, the skate park and the library. Since Kevin lives close to each of these things, he is sure that he can draw them on a map.

Kevin has decided to use a coordinate grid to show each location. He wants to send Charlotte a key that will match each location with its accurate coordinates.

Here is Kevin's grid.

Given this map, which coordinates should Kevin use to name each location?

**Pay close attention to this Concept and you will learn how to write coordinates to name locations.**

### Guidance

When we graphed geometric figures, we used integer coordinates to find the location of each point. Then we graphed each point according to its location. Maps also use integer coordinates to identify different locations. If you look at a map, you will see some numbers and sometimes letters around the border of the map. This can assist you in figuring out the location of cities or even different locations.

**Some maps use integers to identify different locations. Let’s look at a map that does this. Here we have used a coordinate grid to identify where different places are in a town. Let’s look at this map.**

**We can say that Kara’s house is blue, Mark’s house is pink and Chase’s house is green. Each house has coordinates. We can say that the center of each house marks its coordinates on the map.**

**Kara’s house is at (-3, 1)**

**Mark’s house is at (3, -2)**

**Chase’s house is at (3, 4)**

**Local maps use letters and numbers to identify locations. World maps use degrees written in latitude and longitude. Let’s learn about this real life use of coordinates.**

** Longitude** is the measure of lines vertically on a map.

** Latitude** is the measure of lines horizontally on a map.

**We can measure longitude and latitude using degrees. These degrees are written as ordered pairs.**

**Here you can see degrees of latitude as horizontal measures. The degrees of longitude are the vertical measures.**

We can identify different locations on a map if we have the coordinates of the location. Notice that the degrees of latitude are written first, those are the horizontal degrees, and the degrees of longitude are written second. Those are the vertical degrees.

Practice working in degrees. Identify the states according to their locations in latitude and longitude.

#### Example A

\begin{align*}30^\circ, 83^\circ\end{align*}

**Solution:Texas**

#### Example B

\begin{align*}42^\circ, 100^\circ\end{align*}

**Solution: South Dakota**

#### Example C

\begin{align*}30^\circ, 100^\circ\end{align*}

**Solution: Texas**

Now back to the map.

Here is the original problem once again. Reread the problem and then use what you have learned to write the coordinates to match Kevin’s map.

Kevin and his pen pal Charlotte are both creating maps of their neighborhoods to show each other what it looks like where they live. Kevin has decided to name the most important things on his map. He has decided to include his house, his school, the skate park and the library. Since Kevin lives close to each of these things, he is sure that he can draw them on a map.

Kevin has decided to use a coordinate grid to show each location. He wants to send Charlotte a key that will match each location with its accurate coordinates.

Here is the grid that Kevin starts off with.

Given this map, which coordinates should Kevin use to name each location?

**Now that you have finished this Concept, let’s work on writing coordinates to match Kevin’s map.**

**First, let’s start with his home. His house is located at (4, 5).**

**His school is located close to his home at (4, 2)**

**The library is located at (-1, 3).**

**Finally, the skate park is the farthest away from his home at (0, -3).**

**Kevin is ready to send his map and coordinates to Charlotte. He can’t wait to see her map.**

### Vocabulary

Here are the vocabulary words in this Concept.

- Quadrants
- the four sections of a coordinate grid

- Origin
- the place where the \begin{align*}x\end{align*} and \begin{align*}y\end{align*} axis’ meet at (0, 0)

- Ordered Pair
- the \begin{align*}x\end{align*} and \begin{align*}y\end{align*} values used to locate points on a coordinate grid \begin{align*}(x,y)\end{align*}

- \begin{align*}x\end{align*} axis
- the horizontal axis on the coordinate grid

- \begin{align*}y\end{align*} axis
- the vertical axis on the coordinate grid

- Coordinates
- the \begin{align*}x\end{align*} and \begin{align*}y\end{align*} values of an ordered pair

- Longitude
- vertical measure of degrees on a map

- Latitude
- horizontal measure of degrees on a map

### Guided Practice

Which state is at \begin{align*}45^\circ, 70^\circ\end{align*}?

**To answer this question, we start with the horizontal degrees, the latitude. That says \begin{align*}45^\circ\end{align*}. We start at 45 and then move to 70 degrees.**

**You can see that we are at the state of Maine.**

**Maine is our answer.**

**As long as you have values on a map, you can use coordinates to identify any location.**

### Video Review

Here is a video for review.

http://video.about.com/geography/Latitude-and-Longitude.htm - This is a video from about.com on latitude and longitude.

### Practice

Directions: Identify each place on the map according to latitude and longitude.

1. What is at \begin{align*}35^\circ, 70^\circ\end{align*}?

2. What is at \begin{align*}30^\circ, 90^\circ\end{align*}?

3. What is at \begin{align*}85^\circ, 70^\circ\end{align*}?

4. What is at \begin{align*}55^\circ, 90^\circ\end{align*}?

5. What is at \begin{align*}20^\circ, 40^\circ\end{align*}?

6. What is at \begin{align*}40^\circ, 80^\circ\end{align*}?

7. What is at \begin{align*}85^\circ, 100^\circ\end{align*}?

8. What is at \begin{align*}95^\circ, 80^\circ\end{align*}?

9. What is at \begin{align*}95^\circ, 100^\circ\end{align*}?

10. What is at \begin{align*}60^\circ, 30^\circ\end{align*}?

11. What is at \begin{align*}75^\circ, 30^\circ\end{align*}?

12. What is at \begin{align*}45^\circ, 40^\circ\end{align*}?

13. What is at \begin{align*}45^\circ, 45^\circ\end{align*}?

14. What is at \begin{align*}50^\circ, 70^\circ\end{align*}?

15. What is at \begin{align*}80^\circ, 50^\circ\end{align*}?