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?

   • 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.
   • Yes, it is a right triangle, because the two shorter sides together are longer than 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, because the two shorter sides together are longer than 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.
   • 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.
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, 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.
   • You cannot tell without measuring the angles.
4. 4.

   Milo's math book shows a triangle with sides 48, 52 and 20 inches, with no angle marked. 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.
   • Yes, it is a right triangle, because the two shorter sides together are longer than the longest.
5. 5.

   33, 44 and 55; 8, 11 and 14; 5, 6 and 7. Noah has three sets of straws to make triangles, in cm. Which set makes a right triangle?

   • Sides 8, 11 and 14
   • Sides 5, 6 and 7
   • Sides 33, 44 and 55
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 10, 12 and 14
   • Sides 40, 42 and 58
   • Sides 6, 7 and 9
7. 7.

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

   • 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.
   • Yes, the corner is square, because the diagonal is the longest side.
8. 8.

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

   • No, the corner is not square: the squares on the two sides do not add up to the square on the diagonal.
   • 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, so it is a right angle.
9. 9.

   Bo's class rug is 24 by 70 inches, and the diagonal is 74 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.
10. 10.

    Esme measures a window 36 by 48 inches; the diagonal is 61 inches. Is the corner square?

    • You cannot tell without a tool that measures angles.
    • Yes, the corner is square, because the diagonal is the longest side.
    • 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.