Small practice
brighter futures.
Checking sign-in status
Menu

Geometry practice

Quadrilateral Angle Sum Worksheets

Find missing interior angles using the 360-degree sum, with diagram or listed-angle formats and optional decimal practice.

Ready-made English PDF · fixed settings

Worksheet · LetterWorksheet · A4
Customize worksheet ↓
With answer key

Customization below makes a separate PDF.

First page of the quadrilateral angle sum worksheets printable worksheetOpen full-size sample (first page)

Fixed English ready-made files. Custom settings below apply only to the configured PDF.

Ready to print

Start with a ready-made worksheet

Find the missing interior angle. The four interior angles of a quadrilateral add to 360 degrees.

Download the practice pages alone, or include a separate answer key or teacher model. Longer activities may use more than one page.

US Letter

Student worksheetWorksheet with answers

A4

Student worksheetWorksheet with answers
Customize this worksheet

Paper sizes and printing help · More geometry activities

Start with 360 degrees

Add the three known interior angles, then subtract their sum from 360 degrees.

Learning objective

What this activity builds

Find an unknown interior angle of a convex quadrilateral.

Worked example

Three interior angles are 74 degrees, 101 degrees and 93 degrees. Find the fourth.

92 degrees.

360 - (74 + 101 + 93) = 92. Check that all four angles total 360 degrees.

Teaching notes

Make the practice count

  • Subtract the sum of the three known angles from 360 degrees.
  • The middle letter in a three-letter angle name is its vertex.
  • Diagram format uses whole degrees; choose listed angles for tenths or hundredths.

Make it yours

Customize the practice

Choose your options, update the preview, then download the exact same pages.

Twelve true convex quadrilaterals ask for one missing interior angle. Decimal choices are available in the named-angle list format; values inside diagrams use whole degrees.

Worksheet settings

Page note and reproducible seed

The same settings and seed make the same questions. Shared links include your page note; leave personal information out.

Configured PDF · Angles in Quadrilaterals · US Letter

Preview ready. Download includes these exact pages.

2 student pages
Enlarged pages scroll. PDF size stays the same.
Math SheetNameScoreTeacherDateAngles in QuadrilateralsUse the 360-degree sum of the interior angles to find each missing angle.1. Find the angle marked X.ABCDX94°50°106°angle DAB =2. Find the angle marked X.ABCD106°X68°77°angle ABC =3. Find the angle marked X.ABCD56°109°X91°angle BCD =4. Find the angle marked X.ABCD81°52°107°Xangle CDA =5. Find the angle marked X.ABCDX86°67°112°angle DAB =6. Find the angle marked X.ABCD86°X75°97°angle ABC =The interior angles of every quadrilateral sum to 360 degrees.math-sheet.comPage 1 of 2
Math SheetNameScoreTeacherDateAngles in QuadrilateralsUse the 360-degree sum of the interior angles to find each missing angle.7. Find the angle marked X.ABCD95°101°X87°angle BCD =8. Find the angle marked X.ABCD78°69°86°Xangle CDA =9. Find the angle marked X.ABCDX84°108°94°angle DAB =10. Find the angle marked X.ABCD90°X56°114°angle ABC =11. Find the angle marked X.ABCD63°95°X110°angle BCD =12. Find the angle marked X.ABCD89°104°55°Xangle CDA =The interior angles of every quadrilateral sum to 360 degrees.math-sheet.comPage 2 of 2

A useful next step

Related activities

First page preview: Parallelogram Properties Worksheets

Geometry

Parallelogram Properties Worksheets

Use consecutive angles, opposite sides, bisected diagonals and diagonal-split angles in direct or algebra practice.

Preview and download
First page preview: Trapezoid Properties Worksheets

Geometry

Trapezoid Properties Worksheets

Practice same-leg angles, isosceles-trapezoid diagonals, midsegments and missing bases with direct or algebra questions.

Preview and download
First page preview: Triangle angle sum worksheets

Geometry

Triangle angle sum worksheets

Solve eight exact triangle angle equations with one variable expression and two numeric givens. Choose interior, exterior or mixed placement independently from single-variable, algebraic or mixed expression practice.

Preview and download