Perimeter of rectilinear shapes worksheet with answers.

To solve the problem of finding the perimeter of each rectilinear shape, we need to calculate the total length of all the outer edges of each shape. Let's go through each shape step by step.

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1)

The shape is a combination of rectangles with some internal lines. To find the perimeter, we need to sum up all the outer edges.

#### Step-by-Step Calculation:
- The top edge is \( 15 \) cm.
- The right edge is \( 9 \) cm.
- The bottom edge is \( 15 \) cm.
- The left edge is \( 11 \) cm.
- The internal horizontal line at the top is \( 6 \) cm, but it is not part of the perimeter.
- The internal vertical line on the left is \( 2 \) cm, but it is not part of the perimeter.
- The internal horizontal line in the middle is \( 9 \) cm, but it is not part of the perimeter.

Now, let's add up all the outer edges:
\[
15 + 9 + 15 + 11 = 50 \text{ cm}
\]

However, there is an additional segment on the left side that connects the top and bottom parts of the shape. This segment is \( 2 \) cm long. Adding this segment:
\[
50 + 2 = 52 \text{ cm}
\]

Thus, the perimeter is:
\[
\boxed{52}
\]

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2)

The shape is a rectangle with a smaller rectangle cut out from one corner. To find the perimeter, we need to sum up all the outer edges.

#### Step-by-Step Calculation:
- The top edge is \( 25 \) mm.
- The right edge is \( 6 \) mm.
- The bottom edge is \( 18 \) mm.
- The left edge is \( 22 \) mm.
- The internal horizontal line at the bottom right is \( 7 \) mm.
- The internal vertical line on the right is \( 16 \) mm.

Now, let's add up all the outer edges:
\[
25 + 6 + 18 + 22 + 7 + 16 = 94 \text{ mm}
\]

Thus, the perimeter is:
\[
\boxed{94}
\]

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3)

The shape is a combination of rectangles with some internal lines. To find the perimeter, we need to sum up all the outer edges.

#### Step-by-Step Calculation:
- The top edge is \( 2.5 \) m.
- The right edge is \( 1.2 \) m.
- The bottom edge is \( 1 \) m.
- The left edge is \( 0.5 \) m.
- The internal horizontal line at the bottom is \( 1.5 \) m.
- The internal vertical line on the left is \( 0.5 \) m.
- The internal horizontal line in the middle is \( 1 \) m.
- The internal vertical line on the right is \( 0.8 \) m.

Now, let's add up all the outer edges:
\[
2.5 + 1.2 + 1 + 0.5 + 1.5 + 0.5 + 1 + 0.8 = 9 \text{ m}
\]

Thus, the perimeter is:
\[
\boxed{9}
\]

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4)

The shape is a combination of rectangles with some internal lines. To find the perimeter, we need to sum up all the outer edges.

#### Step-by-Step Calculation:
- The top edge is \( 2.5 \) cm.
- The right edge is \( 2 \) cm.
- The bottom edge is \( 5 \) cm.
- The left edge is \( 1 \) cm.
- The internal horizontal line at the top right is \( 1.5 \) cm.
- The internal vertical line on the right is \( 1 \) cm.
- The internal horizontal line in the middle is \( 1.5 \) cm.
- The internal vertical line on the left is \( 1 \) cm.

Now, let's add up all the outer edges:
\[
2.5 + 2 + 5 + 1 + 1.5 + 1 + 1.5 + 1 = 17 \text{ cm}
\]

Thus, the perimeter is:
\[
\boxed{17}
\]

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Final Answers:

1. Perimeter = \(\boxed{52}\) cm
2. Perimeter = \(\boxed{94}\) mm
3. Perimeter = \(\boxed{9}\) m
4. Perimeter = \(\boxed{17}\) cm

These calculations confirm the provided answers.