Acute, right or obtuse from the sides, Pythagorean triples, and 45-45-90 and 30-60-90 triangles

Answer Key - Grade 10 Math Worksheet

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

1. 1.

   Ari has two straws, 6 cm and 8 cm long. Which length for a third straw makes an obtuse triangle?

   • 9 cm
   • 15 cm
   • 12 cm
   • 10 cm
2. 2.

   Bo has two straws, 5 cm and 12 cm long. Which length for a third straw makes an obtuse triangle?

   • 18 cm
   • 14 cm
   • 13 cm
   • 12 cm
3. 3.

   Esme has two straws, 9 cm and 12 cm long. Which length for a third straw makes an obtuse triangle?

   • 22 cm
   • 13 cm
   • 17 cm
   • 15 cm
4. 4.

   Jun has two straws, 8 cm and 15 cm long. Which length for a third straw makes an obtuse triangle?

   • 16 cm
   • 19 cm
   • 17 cm
   • 24 cm
5. 5.

   Luz draws a square so that all four corners touch the edge of a round clock face with radius 6 cm. What is the area of the square, in square centimeters?

   72 square centimeters
6. 6.

   Milo draws a square so that all four corners touch the edge of a round plate with radius 7 cm. What is the area of the square, in square centimeters?

   98 square centimeters
7. 7.

   Noah draws a square so that all four corners touch the edge of a round dish with radius 9 cm. What is the area of the square, in square centimeters?

   162 square centimeters
8. 8.

   Pia cuts a rhombus out of felt. Each side is 6 cm and one angle is 60°. What is its area in square centimeters, in simplest radical form?

   18√3
9. 9.

   Tala cuts a rhombus out of felt. Each side is 10 cm and one angle is 60°. What is its area in square centimeters, in simplest radical form?

   50√3
10. 10.

    Zee cuts a rhombus out of felt. Each side is 12 cm and one angle is 60°. What is its area in square centimeters, in simplest radical form?

    72√3