# 3.5 How do I annotate or measure on a 3D model
## Point
Select \[Points], and then click or tap at the desired location to define points.
On the right side, you can view the latitude and longitude coordinates and elevation of the defined point, and you can also change the point name, point colour, etc. according to your working needs.
## Line
Select \[Line], then click the point at the desired location to start drawing, and double-click the point to end drawing.
2D length: the length of the drawn line segment projected onto the ground
3D length: the length of the manually drawn line.
Elevation difference: the difference in height between the two points at which the line segment is plotted
Slope: the value of the angle between the plotted line segment and the reference plane
## Polygon
Select \[Polygon], then click the point at the desired position to start drawing, and double-click the point to end drawing, and draw at least 3 points to form a surface.
3D area: the 3D area of the drawn surface
2D area: the 2D area of the surface formed by projecting the points of the drawn surface onto the ground.
3D perimeter: the sum of the lengths of the hand-drawn points.
2D perimeter: the sum of the lengths of the projected line segments on the ground.
Max. elevation: the height of the highest point among the points clicked in the process of drawing the surface.
Min.elevation: the height of the lowest point among the points clicked in the process of drawing the surface.
Elevation difference: the difference in height between the highest and lowest point.
## Circle
Select \[Circle], then click the point at the desired position to determine the centre of the circle, and double-click to end the drawing to form a circle.
On the right, you can view the radius, 2Darea, and 2D perimeter of the circle, and the longitude, latitude, and height of the Center Coordinates of the circle.
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.get3d.ai/user-help-center/get3d-cloud/detailed-steps/3.5-how-do-i-annotate-or-measure-on-a-3d-model.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.