Question

I need help with number 7 please.

Answer 1

Answer:

• lengths, CW from lower left vertical: 2, 5, 6, 3, 2, 2, 1, 5, 4
• perimeter: 30 m

Step-by-step explanation:

The figure appears to be drawn roughly to scale, so that fact can offer clues.

The triangles both have hypotenuses of 5. The only integer lengths for sides that will give a hypotenuse of 5 are side lengths 3 and 4. Right triangles with side lengths 3 and 4 will have an area of (1/2)(3)(4) = 6.

The rectangle at lower left will not have a side length of 3, so its width is 4. Since its area is 8 (width × height), the height of it must be 2. (The rectangle dimensions must be factors of 8.)

The vertical side of the left triangle is then 3. It appears to be divided so the upper segment (the side of the rectangle of area 6) is 1 and the lower segment (part of the right triangle vertical side) is 2.

Then the vertical side of the right triangle is 4, and its horizontal side (left half of the bottom of the upper rectangle) is 3.

Since the height of the upper rectangle is 1, its width must be 6. Then the little tab hanging down on the right must be 2 by 2 (for an area of 4).

Altogether, we have found the lengths to be as marked in the attachment.

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Summary

The perimeter lengths, CW from the lower left vertical, are ...

  2, 5, 6, 3, 2, 2, 1, 5, 4 . . . . meters

The perimeter is their total: 30 m.