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, 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.
   • You cannot tell without measuring the angles.
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.
   • 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, because the two shorter sides together are longer than the longest.
3. 3.

   Luz's poster triangle has sides of 13, 18 and 12 cm, drawn in bright crayon. 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.
   • 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.
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?

   • 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.
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 33, 44 and 55
   • Sides 5, 6 and 7
   • Sides 8, 11 and 14
6. 6.

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

   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
8. 8.

   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.
   • 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.
   • You cannot tell without a tool that measures angles.
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.
   • Yes, the corner is square: the squares on the two sides add up to the square on the diagonal.
   • You cannot tell without a tool that measures angles.
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: 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.