Back to Geometry and reasoning

Angles, shape properties, symmetry and similar triangles topic check

Practise angles, shape properties, symmetry and similar triangles in G1 Mathematics, check independently, and return later to review. This check covers selected skills, not the whole course topic.

Learning goals
  • Classify angles by their size
  • Apply the sum of angles around a point
  • Deduce all unknown angles at two intersecting lines
  • Connect triangle, rectangle and square facts to deduce angles in a drawn composite figure
  • Connect parallelogram and connected shape facts to deduce angles using existing lines
  • Connect trapezium and connected shape facts to deduce angles using existing lines
  • Use the equal-distance properties of perpendicular bisectors and angle bisectors
  • Produce complete parallel-line angle relations and values from numerical or affine-expression givens
  • Construct geometric figures from stated conditions
  • Give the number of lines of symmetry and the order of rotational symmetry of a plane figure
  • Find a scale factor and unknown lengths from matched sides of similar triangles
  • Reason about congruence, similarity and scale factors
  • G1 Mathematics 2027
Start · Practise · Check · Review

Finding your next step…This check didn’t finish loading. Reload the page to try again.

Your next step

Check what you know

Answer each question and say how sure you are to find what to practise next.

Choose a practice set

Choose a set, then start. You get feedback after each question.

Each set checks only its named skills. You can take the other sets another time.

Check what you know

Start here to see which parts you already know.

Checking question availability…

  • Question count checked before you start
  • Feedback when you submit
Practise first

This shows what to work on next and doesn’t count towards your course progress.

Your work

Without an account, unfinished answers stay in this tab. Signed in, they are saved on this device until the deadline shown when you start.

Report a problem with this question

What's wrong? Tick all that apply.

0 / 1000

Practise

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise after feedback

After a check, practise the skills it showed you need to work on.

Loading your check…

Reload the page if the check does not appear.

Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Parallel-line relationships and angle values · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Similar-triangle scale factors and lengths · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Angle types, angles on a line, at a point and vertically opposite · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Angles in combined triangles · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Angles in parallelograms and trapeziums · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Lines of symmetry and order of rotational symmetry · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Perpendicular bisector and angle bisector properties · Check your progress

When you feel ready, answer on your own to show what you can do.

Loading your check…

Reload the page if the check does not appear.

Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Parallel-line relationships and angle values · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Similar-triangle scale factors and lengths · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Angle types, angles on a line, at a point and vertically opposite · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Angles in combined triangles · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Angles in parallelograms and trapeziums · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Lines of symmetry and order of rotational symmetry · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Perpendicular bisector and angle bisector properties · Check again

After practising what your progress check showed, check those skills again.

Loading your check…

Reload the page if the check does not appear.

Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Parallel-line relationships and angle values · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Similar-triangle scale factors and lengths · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Angle types, angles on a line, at a point and vertically opposite · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Angles in combined triangles · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Angles in parallelograms and trapeziums · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Lines of symmetry and order of rotational symmetry · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Perpendicular bisector and angle bisector properties · Retention check

Come back later to see whether your learning has lasted.

Loading your check…

Reload the page if the check does not appear.

Practise: Parallel-line relationships and angle values

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Similar-triangle scale factors and lengths

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Angle types, angles on a line, at a point and vertically opposite

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Angles in combined triangles

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Angles in parallelograms and trapeziums

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Lines of symmetry and order of rotational symmetry

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Practise: Perpendicular bisector and angle bisector properties

Practise questions on the skills you are learning.

Loading your check…

Reload the page if the check does not appear.

Revision notes

Revise geometry and reasoning

Use angle and symmetry properties, construct triangles and bisectors, and match corresponding parts in congruent or similar figures.

Key ideas

  1. Parallel lines and angle reasons

    Name the geometric condition before using an angle equality or sum.

  2. Angle relations and equations

    Trace every angle pair, choose equality or a sum, and check algebraic results against the geometry.

  3. Line and rotational symmetry

    Test the whole figure under a reflection or rotation and count matching positions in a full turn.

  4. Triangle angle properties

    Use the angle sum and equal-side markings to justify unknown triangle angles.

  5. Parallel quadrilaterals and their angles

    Use marked parallel sides and named quadrilateral properties to justify unknown angles.

  6. Triangle construction from data

    Construct a triangle from stated lengths or angles and check that the data determine a possible figure.

  7. Bisectors and geometric construction

    Use equal distances to justify compass constructions and check the given dimensions.

  8. Congruence and similarity

    Match corresponding parts before comparing lengths, angles and scale.

  9. Similar triangles and unknown lengths

    Match corresponding vertices, find the scale factor and calculate unknown sides in separate, nested and crossed triangles.

What the syllabus asks

From the G1 Mathematics 2027 syllabus

Show all 11 syllabus statements
  • Right, acute, obtuse and reflex angles
  • Vertically opposite angles, angles on a straight line and angles at a point
  • Angles formed by two parallel lines and a transversal: corresponding angles, alternate angles, interior angles
  • Properties of triangles, special quadrilaterals
  • Properties of perpendicular bisectors of line segments and angle bisectors
  • Construction of simple geometrical figures from given data (including perpendicular bisectors and angle bisectors) using compasses, ruler, set squares and protractors, where appropriate
  • Line and rotational symmetry of plane figures
  • Lines of symmetry
  • Order of rotational symmetry
  • Congruent and similar figures
  • Properties of similar triangles and quadrilaterals: ∗ corresponding angles are equal ∗ corresponding sides are proportional