1. Open your sketchpad document. Click anywhere on the document to make sure everything is deselected.

2. Select the Point Tool.

3. Create another point on the top parallel line.
4. Label the point.
Select the Text Tool.

Double Click on the point to open the text box. Type Red Triangle in the Label window.

5. Create two segments connecting the base with the Red Triangle Point.
Select the Segment Tool.

Create the segments.

6. Color the triangle red.
Select the Selection Arrow Tool.

Click anywhere on the document to deselect every object.
Select the vertices.
> Construct
> Triangle Interior
The color should default to yellow so
> Display
> Color
Choose red.
Select anywhere on the document to deselect all objects.
Now you have a red triangle.

I selected Red segments and Yellow segments on each triangle and kept the base blue since each triangle saves the same base.
Drag the points around to make sure objects are connected.