Checkpoint: diagonals, names and building

A parallelogram has diagonals 14 and 10 long. What are the four pieces the crossing makes?

• 7, 7, 7 and 7, because the crossing is in the middle
• 14, 14, 10 and 10, because each diagonal is drawn twice
• 7, 7, 5 and 5

A four-sided shape has two diagonals of exactly the same length. Must it be a rectangle?

• Yes, that is what equal diagonals mean
• Yes, provided one of its corners is 90°
• No — the shape has to be a parallelogram first

A rhombus has diagonals of 24 and 10. What is the crossing angle, and how long are the four pieces?

• It depends on how far the rhombus leans
• 45°, with pieces of 24, 24, 10 and 10
• Exactly 90°, with pieces of 12, 12, 5 and 5

Which of these is true of a square with sides of 6?

• It is a square, and therefore not a rectangle or a rhombus
• It is a square and a rectangle. A rhombus needs sides that lean
• It is a square, a rhombus, a rectangle and a parallelogram. All at once

You are given four side lengths: 7, 4, 5 and 6. You are told to construct the shape. What is missing?

• The area, which fixes how wide the shape opens
• One more measurement, such as the length of a diagonal
• Nothing — four sides settle a shape the way three settle a triangle