Is it a right triangle? (the converse)

Answer Key - Grade 8 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Bo cuts a paper triangle with sides of 9, 4 and 8 cm. What do the squares on the two shorter sides add up to, in square cm?

   80
2. 2.

   Esme trims a felt triangle with sides of 6, 11 and 9 inches. What do the squares on the two shorter sides add up to, in square inches?

   117
3. 3.

   Jun draws a triangle with sides of 7, 9 and 5 cm on a poster. What do the squares on the two shorter sides add up to, in square cm?

   74
4. 4.

   Kira's class ropes off a triangle-shaped flower bed with sides of 11, 7 and 8 feet. What do the squares on the two shorter sides add up to, in square feet?

   113
5. 5.

   Milo glues three paper squares onto the sides of a triangle. Their areas are 20, 45 and 65 square cm. Is the triangle a right triangle?

   • It is a right triangle, because one square is much bigger than the other two.
   • It is not a right triangle: the two smaller squares do not add up to the biggest one.
   • You cannot tell without measuring the angles.
   • It is a right triangle: the two smaller squares add up to the biggest one.
6. 6.

   Noah's quilt has three square patches on the sides of a triangle, 50, 85 and 30 square inches. Is the triangle a right triangle?

   • It is a right triangle, because one square is much bigger than the other two.
   • It is a right triangle: the two smaller squares add up to the biggest one.
   • You cannot tell without measuring the angles.
   • It is not a right triangle: the two smaller squares do not add up to the biggest one.
7. 7.

   Ren's math book shows squares of 36, 50 and 90 square cm on the sides of a triangle. Is the triangle a right triangle?

   • You cannot tell without measuring the angles.
   • It is a right triangle, because one square is much bigger than the other two.
   • It is a right triangle: the two smaller squares add up to the biggest one.
   • It is not a right triangle: the two smaller squares do not add up to the biggest one.
8. 8.

   Tala lists the sides of a triangle as 9, 4 and 7 cm. To test for a right angle, which square must the other two add up to?

   • The square on the side of 4 cm
   • The square on the side of 9 cm
   • The square on the side of 7 cm
9. 9.

   Zee's worksheet gives a triangle's sides as 12, 15 and 10 inches. To test for a right angle, which square must the other two add up to?

   • The square on the side of 12 inches
   • The square on the side of 10 inches
   • The square on the side of 15 inches
10. 10.

    A triangle on Ari's park map has sides of 6, 14 and 11 feet. To test for a right angle, which square must the other two add up to?

    • The square on the side of 6 feet
    • The square on the side of 11 feet
    • The square on the side of 14 feet