A terrarium is a glass container for soil and plants as shown - Leaving Cert DCG - Question C-3 - 2018

Next, draw the elevation of the left-hand terrarium, ensuring the apex of the pyramid aligns with the base in the correct positioning.

Project lines from points A and B horizontally to create X1Y1, which should be parallel to the line where surfaces A and B intersect. Ensure precise measurements for accuracy.

From the intersection, draw a new line X2Y2 that is perpendicular to the intersection line. Label this line clearly for reference.

Finally, project surfaces A and B in line form, clearly indicating the dihedral angle between them. Label the angle accordingly, noting that it will involve measuring and calculating the angle formed.

Utilize the previously drawn outline for surface C. Construct the necessary triangles, ensuring that all sides and angles are congruent to maintain accuracy.

For the right-hand terrarium, begin with a hexagon outline of 150mm side length. Draw the diagonals of the hexagon to assist in elevation projections.

Complete the plan view by drawing an equilateral triangle that connects appropriate points on the hexagon outline, clearly showing the shape as per the specifications.

To visualize the cube's orientation effectively, utilize a semi-circle to display the cube's height in elevation relative to the hexagonal base. This will clarify the relationship between both geometries.

Finally, project the elevation of the entire terrarium structure, ensuring all components are aligned accurately and labeled for clarity, completing the representation.

Indicate that the line X1Y1 is inclined at an angle of 60°. This will serve as a reference for the shapes described in the following steps.

Construct the edge view of surface D, clearly demonstrating its inclination to the horizontal plane, providing visual evidence of its angle.

Conclude by constructing the true shape of surface D based on the angle and observations made in previous steps, ensuring all measurements are accurate and clear.