mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Equal side and angle

In the diagram shown, the lengths \(AD = CD\) and the angles \(ABD=CBD\).
Prove that the lengths \(AB=BC\).

Show answer

If you enjoyed this puzzle, check out Sunday Afternoon Maths XXXVIII,
puzzles about 2d shapes, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2025

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022


List of all puzzles

Tags

bases probabilty even numbers quadrilaterals calculus graphs sport axes 3d shapes regular shapes unit fractions cube numbers arrows medians prime numbers angles tournaments geometric mean routes digital clocks volume cards chocolate perfect numbers coordinates dice polynomials area mean proportion consecutive numbers powers square grids taxicab geometry division binary palindromes multiplication money pascal's triangle factors irreducible numbers remainders crossnumbers multiples symmetry square roots the only crossnumber means sets doubling surds games logic triangle numbers matrices geometry coins pentagons elections integration addition expansions square numbers determinants shapes odd numbers hexagons dates triangles speed people maths tangents balancing polygons books folding tube maps ellipses dodecagons tiling scales averages integers colouring star numbers complex numbers digits grids geometric means trigonometry crosswords menace partitions perimeter ave algebra lists combinatorics advent cryptic crossnumbers functions median lines shape chalkdust crossnumber gerrymandering sums time factorials squares consecutive integers digital products prime factors indices parabolas fractions percentages circles christmas multiplaction squares wordplay albgebra decahedra xor differentiation planes clocks neighbours spheres chess cubics 2d shapes sequences sum to infinity probability floors products dominos rugby cryptic clues number numbers quadratics range rectangles

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2026