Geometry Formula: Area, Volume

Geometry Formula is a clear geometry formulas reference for school and early university: 180 highlighted formulas in 50 topics, from angles and triangles to circles, coordinate geometry and the area and volume of solids.
Every formula is typeset cleanly, every symbol is explained, and 59 original drawings show what the formula means. It all works offline.

Each topic page lists the key geometry formulas, says when to use them and shows them in action with worked examples. Practice questions with tap-to-reveal answers help you check what you have learned, and three formula sheets put the main area, perimeter, surface area and volume formulas on one page each.

What you will learn

• Basic Terms: points, lines and planes, angles and radians, angle pairs, parallel lines and transversals
• Triangles: types of triangles and angle sum, isosceles and equilateral triangles, congruent and similar triangles, triangle centres (centroid, orthocentre, incentre, circumcentre), triangle area formulas including Heron's formula, the Pythagorean theorem and special right triangles
• Trigonometry for Triangles: right-triangle trigonometry (SOH CAH TOA), angles of elevation and depression, the law of sines with the ambiguous case, the law of cosines, solving any triangle
• Quadrilaterals: the quadrilateral family, squares and rectangles, parallelograms and rhombi, trapezoids, kites, cyclic quadrilaterals with Brahmagupta's formula and Ptolemy's theorem
• Polygons: interior and exterior angles, diagonals, regular polygons and the hexagon
• Circles: circumference and area of a circle, arc length, sectors and segments, circle theorems, chords, secants and tangents
• Coordinate Geometry: distance and midpoint formulas, slope and equations of lines, area from coordinates (shoelace formula), the equation of a circle, parabola, ellipse and hyperbola
• Transformations: translations, reflections, rotations, dilations and symmetry
• 3-D Solids: nets and Euler's formula, prisms, cubes and cuboids, cylinders, pyramids, cones, spheres and hemispheres, frustums, Platonic solids, torus and ellipsoid
• Formula Sheets: plane figure formulas (perimeter and area), solid formulas (surface area and volume), coordinate and trig formulas

Features
• 180 highlighted geometry formulas in 50 topics and 10 sections
• Area and volume formulas for every common shape and solid
• 100 worked examples with the steps shown
• 133 practice questions with tap-to-reveal answers
• 59 original drawings: triangle centres, circle theorems, the law of sines, conic sections, cones, frustums, Platonic solids and more
• Search all topics from the home screen
• Dark mode
• Works offline, no account needed
• Available in 8 languages: English, Español, Português, Français, Deutsch, العربية, हिन्दी and Bahasa Indonesia

Who it is for
• Middle school and high school students learning geometry; useful when revising for GCSE maths or the SAT math section
• Early university students who need a quick reminder of an area, volume or trigonometry formula
• Parents, teachers and tutors who want a reliable geometry formula sheet with clear drawings
• Anyone who needs the area of a shape or the volume of a solid for a project at home or at work

Geometry Formula is an independent study aid. Formulas are checked against the OpenStax textbooks Contemporary Mathematics, Precalculus and Algebra and Trigonometry, and standard references. It is not affiliated with any exam board, textbook publisher or school.

Recent changes:
Improved Arabic display: maths, codes and English names in tables now read in the right order.