Map Tools: List of Google maps tools
I have just discovered a real neat set of mapping tools for lots of uses. https://www.mapdevelopers.com/map_tools.php
Fore example, today I was walking around Circle Gardens, a small ring road, with 8 houses on it, and I was asked how big is the circle of land, excluding the road?
So I looked up the postcode and popped in the postcode in the "Draw a Circle" tool and took a stab at it's size (50 metres) and then moved the circle to the area and adjusted it to fit, so now I know, it's actually 48.28 Meters
A YouTube walk through on drawing a circle 
https://www.youtube.com/watch?v=Om7XKn9AKD4
Map Tools: List of Google maps tools
The following list of tools were built by Map Developers taking advange of Google Map
Area Calculator Tool - Click multiple points on a google map drawing the outline of the shape you want the area of. Area is given in square feet, square meters, acres, square kilometers, and square miles.
Distance Calculator Tool - Click multiple points on a google map drawing a path that you want the distance of. Distance is given in feet, meters, kilometers, and miles.
Draw a circle - Enter a radius then click a point or enter an address to draw a circle on a google map.
Elevation Calculator Tool - Works similar to the distance calculator tool, but instead of the distance along the path it shows a graph of elevation points along that path.
Geocode Tool - This tool allows you to enter an address to find the GPS coordinates i.e. latitude and longitude of the address. It also plot the address on a map where it can be moved to adjust the latitude and longitude.
Advanced Google Search - Search for businesses near you by business type, name, or keyword.
Batch Geocode Tool - Enter up to 100 addresses to find the latitude and longitude of multiple addresses quickly.
Reverse Geocode Tool - Click a point on a google map and this tool will return the closest address to that point.
Distance From To Tool - Enter two addresses, cities, states, or zipcodes to calculate the distance between them.
Driving Directions - Show the fastest route between up to 10 locations.
Draw Rectangle - Enter length and width of a rectangle to draw it on a map.
Traffic Map - Overlay the current traffic congestion on a map.
Directions From To Tool - Enter two addresses, cities, states, or zipcodes to find the best route between them.
Bounding Box Tool - Enter a country, state, city, or zipcode to display the smallest box it will fit in.
Mileage Calculator - Calulate the flight mileage and driving milage between to points at the same time.
Embed Tools
Embed Area Calculator - Allows you to customize and place the areaa calculator tool on your website
Embed a Single Location Map - Allows you to embed a map with a single location on a google map onto your website