Perimeter of composite figures worksheet with step-by-step instructions and four shapes to calculate missing sides and total perimeter.

Problem: Calculate the perimeter of each composite figure.

#### Steps to Success:
1. Read and highlight the given information.
2. Observe the diagram and count & label the number of sides.
3. Find the missing side(s).
4. Write the formula for the perimeter: \( P = \text{Sum of All Sides} \).
5. Check to ensure all sides are added correctly.

---

Problem 1:


#### Given:
- Top side: 8 cm
- Left vertical side: 3 cm
- Bottom horizontal side: 5 cm
- Right vertical side: 7 cm
- Inner horizontal side: 10 cm

#### Solution:
1. Identify all sides:
- Top side: 8 cm
- Left vertical side: 3 cm
- Bottom horizontal side: 5 cm
- Right vertical side: 7 cm
- Inner horizontal side: 10 cm

2. Calculate the missing side:
- The inner horizontal side splits the top side into two segments. Let the left segment be \( x \) and the right segment be \( y \).
- From the diagram:
\[
x + y = 8 \quad \text{(total top side length)}
\]
\[
x = 3 \quad \text{(left vertical side)}
\]
\[
y = 10 - 3 = 7 \quad \text{(right segment of the top side)}
\]

3. Perimeter Calculation:
- Sum all the sides:
\[
P = 8 + 3 + 5 + 7 + 10 = 33 \, \text{cm}
\]

#### Answer:
\[
\boxed{33}
\]

---

Problem 2:


#### Given:
- Top side: 12 cm
- Left vertical side: 9 cm
- Bottom horizontal side: 8 cm
- Right vertical side: 7 cm

#### Solution:
1. Identify all sides:
- Top side: 12 cm
- Left vertical side: 9 cm
- Bottom horizontal side: 8 cm
- Right vertical side: 7 cm

2. Calculate the missing side:
- There are no missing sides in this figure.

3. Perimeter Calculation:
- Sum all the sides:
\[
P = 12 + 9 + 8 + 7 = 36 \, \text{cm}
\]

#### Answer:
\[
\boxed{36}
\]

---

Problem 3:


#### Given:
- Top side: 60 mm
- Left vertical side: 15 mm
- Bottom horizontal side: 30 mm
- Right vertical side: 40 mm

#### Solution:
1. Identify all sides:
- Top side: 60 mm
- Left vertical side: 15 mm
- Bottom horizontal side: 30 mm
- Right vertical side: 40 mm

2. Calculate the missing side:
- There are no missing sides in this figure.

3. Perimeter Calculation:
- Sum all the sides:
\[
P = 60 + 15 + 30 + 40 = 145 \, \text{mm}
\]

#### Answer:
\[
\boxed{145}
\]

---

Problem 4:


#### Given:
- Top side: 7½ m
- Left vertical side: 4 m
- Bottom horizontal side: 2 m
- Right vertical side: 1½ m

#### Solution:
1. Identify all sides:
- Top side: 7½ m
- Left vertical side: 4 m
- Bottom horizontal side: 2 m
- Right vertical side: 1½ m

2. Calculate the missing side:
- There are no missing sides in this figure.

3. Perimeter Calculation:
- Sum all the sides:
\[
P = 7.5 + 4 + 2 + 1.5 = 15 \, \text{m}
\]

#### Answer:
\[
\boxed{15}
\]

---

Final Answers:

1. Perimeter = \(\boxed{33}\) cm
2. Perimeter = \(\boxed{36}\) cm
3. Perimeter = \(\boxed{145}\) mm
4. Perimeter = \(\boxed{15}\) m

Boxed Final Answer:
\[
\boxed{33, 36, 145, 15}
\]