Free original lessons
Learn to complete a capitol building drawing using a vertical mirror axis, with a half-drawn plate, symmetry checks, and independent practice.
Mirror symmetry is a reliable way to draw a balanced capitol building. This lesson defines a vertical mirror axis, shows how to transfer points across it, and gives you a convention for judging whether your drawing is symmetric. You will complete a half-drawn capitol, then draw one independently. All measurements are simple and checkable; any numerical values are hypothetical examples you can adjust to your paper size.
Practice materials: Printable downloads are not available for this lesson yet. Use the instructions and four exercises below.
Place your paper in landscape orientation. Draw a light vertical line down the exact center; this is the mirror axis. Every feature you draw on the left must have a matching feature on the right at the same distance from the axis and the same height above the baseline.
Use a simple convention: the baseline is the bottom edge of the building, and the midline is the horizontal line halfway up the main block. X-height means the distance from baseline to midline. Letter styles and decorative details may vary, so symmetry is judged by matching positions and sizes, not by identical line quality.
The printable plate shows the left half of a capitol building already drawn, with the mirror axis and a blank right half. Your task is to complete the right half so that every left-side feature has a mirror partner. Work from large shapes to small details: steps first, then main block, then dome, then flagpole and windows.
Use a ruler to transfer distances. For example, if a window on the left is 3 cm from the axis, its partner on the right is also 3 cm from the axis. If the dome top is 10 cm above the baseline on the left, the dome top on the right is also 10 cm above the baseline. These numbers are hypothetical examples; measure your actual plate.
On the blank panel, draw your own capitol building using the same mirror method. Start with the axis, baseline, and midline. Sketch only the left half first, then transfer points to the right. Keep the building centered on the axis so the mirror check is easy.
A useful check is the fold test: fold the paper along the axis and hold it up to a light. Matching features should line up within a small tolerance you choose, such as 2 mm. This tolerance is a hypothetical example; decide your own based on your tools and paper.
Symmetry can be checked with arithmetic. For any feature, record its distance from the axis on the left and on the right. The two distances should be equal. For example, if the left dome edge is 4 cm from the axis, the right dome edge should also be 4 cm. If the left flagpole base is 0 cm from the axis, the right base is also 0 cm.
Also check heights. A feature at height 6 cm above the baseline on the left should be at height 6 cm on the right. Use the same units throughout, such as centimeters or grid squares. Keep a simple table of left and right measurements to spot mismatches quickly.
A half-drawn capitol shows a left dome edge 5 cm from the axis at height 8 cm above the baseline. The left flagpole base is on the axis at height 12 cm. Where should the right dome edge and right flagpole base be placed?
The right dome edge should be 5 cm from the axis at height 8 cm above the baseline. The right flagpole base should be on the axis at height 12 cm above the baseline.
On a half-drawn plate, the left main block corner is 6 cm from the axis at height 4 cm above the baseline. Where is the matching right corner?
6 cm from the axis on the right, at height 4 cm above the baseline.
Why: Mirror symmetry requires equal distance from the axis and equal height above the baseline.
Check: Measure the right corner's distance from the axis and its height; both should equal the left values.
A left window is 2 cm from the axis at height 3 cm. A right window is drawn 3 cm from the axis at height 3 cm. Is it symmetric?
No. The right window should be 2 cm from the axis, not 3 cm.
Why: The heights match, but the distances from the axis differ, so the pair is not mirror-symmetric.
Check: Compare the two distances from the axis; they must be equal.
The left dome top is on the axis at height 10 cm. The right dome top is drawn 1 cm to the right of the axis at height 10 cm. What correction is needed?
Move the right dome top onto the axis at height 10 cm.
Why: A point on the axis mirrors to the same point on the axis; a 1 cm offset breaks symmetry.
Check: Measure the right dome top's distance from the axis; it should be 0 cm.
After drawing, the left steps are 4 cm from the axis and the right steps are 4.2 cm from the axis. Your chosen tolerance is 2 mm. Is the drawing acceptable?
No. The difference is 0.2 cm, which equals 2 mm, so it is at the tolerance limit; adjust to make the distances equal.
Why: 0.2 cm equals 2 mm. The tolerance is 2 mm, so the pair is borderline and should be corrected for clear symmetry.
Check: Subtract the smaller distance from the larger; compare the result with your tolerance.
Symmetry is about matching positions and sizes across the axis. Line quality and small stylistic choices may vary; use the fold test and distance measurements to judge balance.
No. Use any consistent unit, such as centimeters, inches, or grid squares. Keep the same unit for all measurements.
Choose a tolerance that suits your tools, such as 2 mm. This is a hypothetical example; state your tolerance and apply it consistently.
The exercise focuses on mirror symmetry. Keep major features mirrored; small decorative variations are allowed under the stated convention.