Boba Maths

Year 6 · Summer term · Shape · Step 4

Year 6 Angles in a triangle worksheets

Find missing angles using the angle sum of a triangle. A free editable Word sheet with eight fluency and six reasoning questions. The answers follow the questions: the same sheet again with every answer in red.

Download the worksheets

Print on A4 portrait: every page carries the sheet twice, side by side, so you can cut down the middle and two pupils each get a half to stick in their books. Every question sits in its own box and pupils write their answers in their book. The answers follow the questions in the file: the same sheet again with every answer in red. It opens in Word, Google Docs, Pages and LibreOffice, so you can change numbers, delete questions or add your own. There is no scaffolded version of this step yet.

Not scaffolded sheet

First page of the not scaffolded Angles in a triangle sheet, printed twice side by side

The same questions without the extra support. For pupils working at the expected standard: eight fluency questions first, then the reasoning questions.

Answer in your book (.docx)

Sample questions from this step

These are real questions from the first set of the sheet (two from the fluency page, two from the reasoning page). Open each one to see the answer.

  1. The three angles of a triangle are shown.
    71°69°40°
    a) What is the sum of the three angles? ____
    Show the answer

    180

  2. This triangle has a right angle. Work out the size of angle z.
    20°z
    z = ____ °
    Show the answer

    70

  3. This triangle has a right angle.
    60°p
    p = 120° because angles in a triangle add up to 180° and 180 − 60 = 120.
    Is Boba correct? Circle yes or no.
    Circle yes or no.
    Explain how you know.
    Show the answer

    No; There is also a right angle of 90°. 180 − 90 − 60 = 30, so p = 30°, not 120°.

  4. Can a triangle have these three angles? Write yes or no.
    a) 29°, 85° and 76° ____
    b) 70°, 45° and 84° ____
    c) 29°, 85° and 66° ____
    Show the answer

    No; No; Yes

What is on each sheet

  • Fluency: eight questions that start easy and get harder, with the key skill of the step practised in different ways.
  • Reasoning: questions with pictures, tables and number lines (spot the mistake, true or false and explain, puzzles with one answer, an open-ended task).
  • Answers in the same file: the sheet again with every answer in red, so there is only one file to download.
  • Boba characters give the instructions in speech bubbles. They are decoration only.

Why one set of questions?

More in Shape

All Shape steps · Year 6 overview