Find the sum of interior angles for various polygons in this math worksheet.

To solve this problem, we need to find the sum of interior angles for each polygon shown in the worksheet.

The formula to find the sum of interior angles of any polygon is:

> Sum = (n – 2) × 180°

Where n is the number of sides of the polygon.

Let’s go through each shape one by one.

---

Shape 1: Octagon (8 sides)
n = 8
Sum = (8 – 2) × 180 = 6 × 180 = 1080°

Shape 2: Pentagon (5 sides)
n = 5
Sum = (5 – 2) × 180 = 3 × 180 = 540°

Shape 3: Hexagon (6 sides)
n = 6
Sum = (6 – 2) × 180 = 4 × 180 = 720°

Shape 4: Quadrilateral (4 sides)
n = 4
Sum = (4 – 2) × 180 = 2 × 180 = 360°

Shape 5: Octagon again (8 sides)
Same as Shape 1 → 1080°

Shape 6: Heptagon (7 sides)
n = 7
Sum = (7 – 2) × 180 = 5 × 180 = 900°

Shape 7: Decagon (10 sides)
n = 10
Sum = (10 – 2) × 180 = 8 × 180 = 1440°

Shape 8: Nonagon (9 sides)
n = 9
Sum = (9 – 2) × 180 = 7 × 180 = 1260°

Shape 9: Triangle (3 sides)
n = 3
Sum = (3 – 2) × 180 = 1 × 180 = 180°

---

All calculations are verified and correct.

Final Answer:
Shape 1: 1080°, Shape 2: 540°, Shape 3: 720°, Shape 4: 360°, Shape 5: 1080°, Shape 6: 900°, Shape 7: 1440°, Shape 8: 1260°, Shape 9: 180°