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8th grade Is it a right triangle? (the converse) worksheet

6 printable versionsChallenge Me10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

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Is it a right triangle? (the converse)

Grade 8 Math Worksheet - Challenge Me

NameDate

Circle the best answer.

  1. Jun's class marks a triangle-shaped herb bed with sides of 1.5, 3.6 and 3.9 meters. Is it a right triangle?

    • No, it is not a right triangle, because its sides are not whole numbers.
    • You cannot tell without measuring the angles.
    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.

  2. Luz cuts a big paper triangle for a banner, with sides of 0.8, 1.5 and 1.8 meters. Is it a right triangle?

    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
    • You cannot tell without measuring the angles.
    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.
    • No, it is not a right triangle, because its sides are not whole numbers.

  3. Milo's kite frame is a triangle with sides of 1.4, 2 and 2.5 meters. Is it a right triangle?

    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.
    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
    • You cannot tell without measuring the angles.
    • No, it is not a right triangle, because its sides are not whole numbers.

  4. Noah's triangle has sides of 4, 7 and √65 cm. Is it a right triangle?

    • You cannot tell without measuring the angles.
    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.
    • No, it is not a right triangle, because √65 cannot be squared.

  5. Pia draws a triangle with sides 3, 5 and √30 cm. Is it a right triangle?

    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
    • No, it is not a right triangle, because √30 cannot be squared.
    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.
    • You cannot tell without measuring the angles.

  6. Tala's robot draws a triangle with sides 5, 6 and √50 cm. Is it a right triangle?

    • No, it is not a right triangle, because √50 cannot be squared.
    • No, it is not a right triangle: the squares on the two shorter sides do not add up to the square on the longest.
    • You cannot tell without measuring the angles.
    • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.

  7. Zee tests a paper triangle with sides 36, 77 and 85 cm, and it passes: it is a right triangle. Where is the right angle?

    • The corner where the sides of 77 and 85 cm meet
    • The corner where the sides of 36 and 85 cm meet
    • The corner where the sides of 36 and 77 cm meet

  8. Ari's pencil triangle has sides 13, 84 and 85 cm, and it is a right triangle. Where is the right angle?

    • The corner where the sides of 13 and 85 cm meet
    • The corner where the sides of 84 and 85 cm meet
    • The corner where the sides of 13 and 84 cm meet

  9. A quilt patch is a right triangle with sides 39, 80 and 89 inches. Bo wants to sew the square corner first. Where is the right angle?

    • The corner where the sides of 80 and 89 inches meet
    • The corner where the sides of 39 and 89 inches meet
    • The corner where the sides of 39 and 80 inches meet

  10. Esme cuts a right triangle with sides 60, 63 and 87 cm. Where is the right angle?

    • The corner where the sides of 63 and 87 cm meet
    • The corner where the sides of 60 and 63 cm meet
    • The corner where the sides of 60 and 87 cm meet
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8th grade Is it a right triangle? (the converse) worksheet – printable
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About this worksheet

Is it a right triangle? (the converse). Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can find the longest side, wherever it is listed, and square every side.
  • I can decide whether a triangle has a right angle: the two smaller squares must add up to exactly the biggest.
  • I can say where the right angle is (across from the longest side) and check a square corner in a real frame.

Standard: 8.G.B.6 (the converse)

Words to know

right triangle: A triangle with one square corner.

converse: The theorem turned around: if the squares add up, there is a right angle.

longest side: The side whose square must equal the other two squares together.

square corner: A right angle, like the corner of a door frame.

near miss: Squares that come close but are not equal: not a right triangle.

Common mistakes

Your child added the side lengths instead of their squares. The test for a right triangle adds the squares on the two shorter sides. Try it on a 3, 4, 5 triangle: 9 + 16 = 25.

Your child squared and added, but used the longest side. The test adds the squares on the two shorter sides and compares them with the square on the longest side. Point to the longest side together first.

Your child said the triangle is not right when the two smaller squares add up exactly to the biggest. Equal sums always mean a right angle. Add the two smaller squares together and compare.

Questions parents ask

What is the most common mistake with is it a right triangle? (the converse)?

Your child added the side lengths instead of their squares. The test for a right triangle adds the squares on the two shorter sides. Try it on a 3, 4, 5 triangle: 9 + 16 = 25.

Are these 8th grade math worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

More grade 8 math

See all grade 8 math

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