Reading the marks on a diagram worksheet
A diagram is not drawn to scale, so only its marks can be trusted. Matching tick marks mean congruent sides, matching arcs mean congruent angles, matching arrowheads mean parallel sides, and a small square means a right angle. Two ticks only match other sides with two ticks.
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Pick more than one for a sheet that mixes them.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep
Sigma Prep · sigmaprep.io/worksheets Name What the Marks Tell YouDate Period List everything the marks tell you.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name What the Marks Tell YouAnswer keyVersion 1Date Period List everything the marks tell you.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
A trapezoid with one arrow on and , and one tick on and
- The arrows pair AB with DC: they are parallel.
- The single ticks pair AD with BC: they are congruent.
The answer is .
Where students go wrong
Reading the shape instead of the marks. A figure that looks like a rectangle is only known to have right angles where the squares are, and sides that look equal are only congruent when they carry the same tick marks.
Also called geometric marks, reading diagrams, tick marks, congruence marks or what can you conclude from the diagram.