Grade 7 · Math

7th grade Can these sides and angles make a triangle? worksheet

6 printable versionsBuilding Confidence10 questions · answer keyFree · no account

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Can these sides and angles make a triangle?

Grade 7 Math Worksheet - Building Confidence

NameDate

Circle the best answer.

1.
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?
- Exactly one triangle: only one size and shape fits
- More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
2.
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?
- More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
- Exactly one triangle: only one size and shape fits
3.
Milo wants to draw a kite wing with angles of 35°, 55° and 90°. Which describes the triangles Milo can draw?
- More than one triangle: different sizes or shapes fit
- No triangle: nothing fits
- Exactly one triangle: only one size and shape fits
4.
Pia wants to draw a tent end with angles of 45°, 50° and 85°. Which describes the triangles Pia can draw?
- More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
- No triangle: nothing fits
5.
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?
- More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
- No triangle: nothing fits
6.
Ari draws a side of 10 cm, then wants angles of 35° and 85° at its two ends. Which describes the triangles Ari can draw?
- No triangle: nothing fits
- More than one triangle: different sizes or shapes fit
- Exactly one triangle: only one size and shape fits
7.
Noah draws a toy boat sail. Noah knows angles of 30° and 60°, and the 9 cm side that joins their two corners. What parts does Noah know?
- Two sides and the angle between them
- Three angles
- Two angles and the side between them
8.
Zee measures the three edges of a tent end: 6 cm, 8 cm and 10 cm. What parts does Zee know?
- Three angles
- Two sides and the angle between them
- Three sides
9.
Pia measures the three corners of a kite wing: 40°, 60° and 80°. What parts does Pia know?
- Three angles
- Three sides
- Two angles and the side between them
10.
Esme draws a 6 cm side, a 9 cm side and a 30° angle. The angle is not where the two sides meet. What parts does Esme know?
- Three angles
- Two sides and the angle between them
- Two sides and an angle not between them

7th grade Can these sides and angles make a triangle? worksheet – printable — Print: 1 2 3 4 5 6

About this worksheet

Can these sides and angles make a triangle?. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

I can check three sides: the two shorter ones must add to more than the longest, and then they make exactly one triangle.
I can check angles: three angles that add to 180° make many triangles (a small one and a big one), and two angles plus a side make exactly one.
I can tell when two sides and an angle make one triangle (angle between them), none, or more than one (angle not between them).

Standard: 7.G.A.2

Words to know

side: One edge of a triangle. A length such as 8 cm tells how long it is.

angle: The opening at a corner, measured in degrees. A triangle's three angles add to 180°.

between: An angle is between two sides when those two sides meet at its corner.

unique: Only one triangle fits. Any other one is the same shape and size, turned or flipped.

more than one: Different triangles fit: the same angles can make a small and a big triangle.

close up: The ends meet, so the sides make a triangle. Short sides can't reach and close up.

swinging side: A side that turns from a fixed point like a compass arm, touching the base.

Common mistakes

Your child thought three angles that add to 180° make just one triangle. Draw a small triangle and a big one with the same three corners: the angles match, but the sizes do not.

Your child thought three side lengths can build more than one triangle. Try it with three straws: however you move them, the triangle comes out the same shape and size.

Your child did not check the angles against 180°.

What to say

Ask: what do the angles add to, and is there room for a triangle?

Questions parents ask

What is the most common mistake with can these sides and angles make a triangle??

Your child thought three angles that add to 180° make just one triangle. Draw a small triangle and a big one with the same three corners: the angles match, but the sizes do not.

Are these 7th grade math worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

More grade 7 math

See all grade 7 math

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