Can three lengths make a triangle?
Grade 8 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.
Kira cuts paper strips for an isosceles triangle. The base is 12 cm, and each equal side is a whole number of cm. What is the shortest each equal side can be?
Luz cuts pieces of yarn for an isosceles triangle. The base is 7 cm, and each equal side is a whole number of cm. What is the shortest each equal side can be?
Labeled sketch, not to scale: the base is 7 cm; two equal sides marked ? cm meet above it. Labeled sketch, not to scale: the base is 7 cm; two equal sides marked ? cm meet above it. 7 cm ? cm ? cm Not to scale. Milo picks pencils for an isosceles triangle. The base is 15.6 cm, and each equal side is a whole number of cm. What is the shortest each equal side can be?
Labeled sketch, not to scale: the base is 15.6 cm; two equal sides marked ? cm meet above it. Labeled sketch, not to scale: the base is 15.6 cm; two equal sides marked ? cm meet above it. 15.6 cm ? cm ? cm Not to scale. Noah cuts paper strips of (x + 2) cm, 7 cm and 12 cm for a triangle. So x is more than ? and less than ?. Type both numbers, smaller first.
Labeled sketch, not to scale: a triangle with sides (x + 2) cm, 7 cm and 12 cm. Labeled sketch, not to scale: a triangle with sides (x + 2) cm, 7 cm and 12 cm. (x + 2) cm 7 cm 12 cm Not to scale Ren cuts paper strips of (x − 1) cm, 6 cm and 10 cm for a triangle. So x is more than ? and less than ?. Type both numbers, smaller first.
Labeled sketch, not to scale: a triangle with sides (x − 1) cm, 6 cm and 10 cm. Labeled sketch, not to scale: a triangle with sides (x − 1) cm, 6 cm and 10 cm. (x − 1) cm 6 cm 10 cm Not to scale Tala cuts pieces of yarn of 2x cm, 8 cm and 14 cm for a triangle. So x is more than ? and less than ?. Type both numbers, smaller first.
Labeled sketch, not to scale: a triangle with sides 2x cm, 8 cm and 14 cm. Labeled sketch, not to scale: a triangle with sides 2x cm, 8 cm and 14 cm. 2x cm 8 cm 14 cm Not to scale Zee's triangle of paper strips has sides of 5 cm and 9 cm and a third side that works. Its perimeter is more than ? cm and less than ? cm. Smaller first.
Labeled sketch, not to scale: the 5 cm and 9 cm paper strips meet at one corner; the third side is marked ? cm. Labeled sketch, not to scale: the 5 cm and 9 cm paper strips meet at one corner; the third side is marked ? cm. 9 cm 5 cm ? cm Not to scale. Ari's triangle of pieces of yarn has sides of 3.5 cm and 6 cm and a third side that works. Its perimeter is more than ? cm and less than ? cm. Smaller first.
Labeled sketch, not to scale: the 3.5 cm and 6 cm pieces of yarn meet at one corner; the third side is marked ? cm. Labeled sketch, not to scale: the 3.5 cm and 6 cm pieces of yarn meet at one corner; the third side is marked ? cm. 3.5 cm 6 cm ? cm Not to scale. Bo's triangle of paper strips has sides of 7 cm and 9 cm and a third side that works. Its perimeter is more than ? cm and less than ? cm. Smaller first.
Labeled sketch, not to scale: the 7 cm and 9 cm paper strips meet at one corner; the third side is marked ? cm. Labeled sketch, not to scale: the 7 cm and 9 cm paper strips meet at one corner; the third side is marked ? cm. 7 cm 9 cm ? cm the 7 cm and 9 cm paper strips meet at one corner Not to scale. Esme's triangle of pencils has sides of 4.5 cm and 10 cm and a third side that works. Its perimeter is more than ? cm and less than ? cm. Smaller first.
Labeled sketch, not to scale: the 4.5 cm and 10 cm pencils meet at one corner; the third side is marked ? cm. Labeled sketch, not to scale: the 4.5 cm and 10 cm pencils meet at one corner; the third side is marked ? cm. 10 cm 4.5 cm ? cm Not to scale.