Is it a right triangle? (the converse)

Grade 8 Math Worksheet

Circle the best answer.

1. 1.

   Esme cuts a triangle from paper with sides of 50, 14 and 48 cm. Is it a right triangle?

   • You cannot tell without measuring the angles.
   • Yes, it is a right triangle, because the two shorter sides together are longer than 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.
   • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
2. 2.

   Jun's felt triangle has sides of 11, 15 and 10 inches. 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, so it has a square corner.
   • 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, because the two shorter sides together are longer than the longest.
3. 3.

   Kira draws a triangle with sides 36, 45 and 27 cm using a sharp pencil. 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: 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, because the two shorter sides together are longer than the longest.
4. 4.

   Luz's poster triangle has sides of 13, 18 and 12 cm, drawn in bright crayon. 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.
   • You cannot tell without measuring the angles.
   • Yes, it is a right triangle, because the two shorter sides together are longer than the longest.
   • Yes, it is a right triangle: the squares on the two shorter sides add up to the square on the longest.
5. 5.

   Milo's math book shows a triangle with sides 48, 52 and 20 inches, with no angle marked. Is it a right triangle?

   • You cannot tell without measuring the angles.
   • Yes, it is a right triangle, because the two shorter sides together are longer than the longest.
   • 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.
6. 6.

   40, 42 and 58; 6, 7 and 9; 10, 12 and 14. Pia's worksheet lists three triangles by their sides, in cm. Which one is a right triangle?

   • Sides 40, 42 and 58
   • Sides 10, 12 and 14
   • Sides 6, 7 and 9
7. 7.

   16, 63 and 65; 9, 11 and 14; 7, 8 and 9. Ren's math book gives three triangles' sides in inches. Which one is a right triangle?

   • Sides 16, 63 and 65
   • Sides 7, 8 and 9
   • Sides 9, 11 and 14
8. 8.

   24, 45 and 51; 9, 10 and 14; 4, 5 and 6. Tala's robot offers three sets of sides, in cm, and waits politely. Which set makes a right triangle?

   • Sides 24, 45 and 51
   • Sides 9, 10 and 14
   • Sides 4, 5 and 6
9. 9.

   Zee builds a model door frame, 45 cm by 60 cm, and the diagonal measures 75 cm. Is the corner square?

   • Yes, the corner is square, because the diagonal is the longest side.
   • You cannot tell without a tool that measures angles.
   • Yes, the corner is square: the squares on the two sides add up to the square on the diagonal.
   • No, the corner is not square: the squares on the two sides do not add up to the square on the diagonal.
10. 10.

    Ari checks a table top 40 inches by 42 inches; its diagonal is 57 inches. Is the corner square?

    • Yes, the corner is square, because the diagonal is the longest side.
    • No, the corner is not square: the squares on the two sides do not add up to the square on the diagonal.
    • You cannot tell without a tool that measures angles.
    • Yes, the corner is square: the squares on the two sides add up to the square on the diagonal, so it is a right angle.