Can these sides and angles make a triangle?
Grade 7 Math Worksheet - Building Confidence

Circle the best answer.
Bo has three pieces of yarn that are 9 cm, 12 cm and 7 cm long. Which describes the triangles Bo can build with them as sides?
- More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
- Exactly one triangle: only one size and shape fits
Esme tears three paper strips (one is very sparkly) that are 6 cm, 3 cm and 12 cm long. Which describes the triangles Esme can build with them as sides?
Labeled sketch, not to scale: three strips of 3 cm, 6 cm and 12 cm; the 3 cm and 6 cm strips are laid end to end along the 12 cm strip, reaching 9 cm. Written beside it: the two shorter sides add to 9 cm; the longest side is 12 cm. Labeled sketch, not to scale: three strips of 3 cm, 6 cm and 12 cm; the 3 cm and 6 cm strips are laid end to end along the 12 cm strip, reaching 9 cm. Written beside it: the two shorter sides add to 9 cm; the longest side is 12 cm. Labeled sketch, not to scale 3 cm 6 cm 12 cm 9 cm the two shorter sides add to 9 cm; the longest side is 12 cm. - More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
- No triangle: nothing fits
Kira folds three paper strips that are 9 cm, 14 cm and 5 cm long. Which describes the triangles Kira can build with them as sides?
Labeled sketch, not to scale: three strips of 5 cm, 9 cm and 14 cm; the 5 cm and 9 cm strips are laid end to end along the 14 cm strip, reaching 14 cm. Written beside it: the two shorter sides add to 14 cm; the longest side is 14 cm. Labeled sketch, not to scale: three strips of 5 cm, 9 cm and 14 cm; the 5 cm and 9 cm strips are laid end to end along the 14 cm strip, reaching 14 cm. Written beside it: the two shorter sides add to 14 cm; the longest side is 14 cm. 5 cm 9 cm 14 cm the two shorter sides add to 14 cm; the longest side is 14 cm Not to scale. - More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
- No triangle: nothing fits
Luz stretches three pieces of yarn that are 13 cm, 9 cm and 4 cm long. Which describes the triangles Luz can build with them as sides?
Labeled sketch, not to scale: three strips of 4 cm, 9 cm and 13 cm; the 4 cm and 9 cm strips are laid end to end along the 13 cm strip, reaching 13 cm. Written beside it: the two shorter sides add to 13 cm; the longest side is 13 cm. Labeled sketch, not to scale: three strips of 4 cm, 9 cm and 13 cm; the 4 cm and 9 cm strips are laid end to end along the 13 cm strip, reaching 13 cm. Written beside it: the two shorter sides add to 13 cm; the longest side is 13 cm. 4 cm 9 cm 13 cm the two shorter sides add to 13 cm; the longest side is 13 cm. Not to scale. - Exactly one triangle: only one size and shape fits
- More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
Milo wants to draw a kite wing with angles of 35°, 55° and 90°. Which describes the triangles Milo can draw?
Labeled sketch, not to scale: a triangle outline with its three corners marked 35°, 55° and 90°. Written beside it: the three angles add to 180°; a triangle's angles add to 180°. Labeled sketch, not to scale: a triangle outline with its three corners marked 35°, 55° and 90°. Written beside it: the three angles add to 180°; a triangle's angles add to 180°. 35° 55° 90° Not to scale - More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
- Exactly one triangle: only one size and shape fits
Tala draws a side of 8 cm, then wants angles of 50° and 70° at its two ends. Which describes the triangles Tala can draw?
Labeled sketch, not to scale: a side of 8 cm with an angle of 50° at one end and an angle of 70° at the other end, both opening upward. Written beside it: the two angles add to 120°; a triangle's angles add to 180°. Labeled sketch, not to scale: a side of 8 cm with an angle of 50° at one end and an angle of 70° at the other end, both opening upward. Written beside it: the two angles add to 120°; a triangle's angles add to 180°. 8 cm 50° 70° Not to scale - More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
- No triangle: nothing fits
Bo sketches a side of 9 cm, then wants angles of 120° and 80° at its two ends. Which describes the triangles Bo can draw?
Labeled sketch, not to scale: a side of 9 cm with an angle of 120° at one end and an angle of 80° at the other end, both opening upward. Written beside it: the two angles add to 200°; a triangle's angles add to 180°. Labeled sketch, not to scale: a side of 9 cm with an angle of 120° at one end and an angle of 80° at the other end, both opening upward. Written beside it: the two angles add to 200°; a triangle's angles add to 180°. 9 cm 120° 80° Not to scale - More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
- Exactly one triangle: only one size and shape fits
Jun measures a triangle on a map: a 5 cm side, a 7 cm side and a 40° angle where those two sides meet. What parts does Jun know?
Labeled sketch, not to scale: a triangle corner where a 5 cm side and a 7 cm side meet at a 40° angle. Labeled sketch, not to scale: a triangle corner where a 5 cm side and a 7 cm side meet at a 40° angle. 5 cm 7 cm 40° Not to scale. - Two sides and an angle not between them
- Three sides
- Two sides and the angle between them
Zee measures the three edges of a tent end: 6 cm, 8 cm and 10 cm. What parts does Zee know?
Labeled sketch, not to scale: a triangle with its three sides labeled 6 cm, 8 cm and 10 cm. Labeled sketch, not to scale: a triangle with its three sides labeled 6 cm, 8 cm and 10 cm. 6 cm 8 cm 10 cm Not to scale - Two sides and the angle between them
- Three angles
- Three sides
Pia measures the three corners of a kite wing: 40°, 60° and 80°. What parts does Pia know?
Labeled sketch, not to scale: a triangle with its three corners marked 40°, 60° and 80°. Labeled sketch, not to scale: a triangle with its three corners marked 40°, 60° and 80°. 40° 60° 80° Not to scale - Two angles and the side between them
- Three sides
- Three angles