Find the measure of each interior angle of each regular polygon. \( \begin{array}{lll}\text { 21. dodecagon } & \text { 22. pentagon } & \text { 23. decagon }\end{array} \)

To find the measure of each interior angle of a regular polygon, you can use the formula: \[ \text{Interior angle} = \frac{(n-2) \times 180}{n} \] where \( n \) is the number of sides of the polygon. 1. For a dodecagon (12 sides): \[ \text{Interior angle} = \frac{(12-2) \times 180}{12} = \frac{10 \times 180}{12} = 150^\circ \] 2. For a pentagon (5 sides): \[ \text{Interior angle} = \frac{(5-2) \times 180}{5} = \frac{3 \times 180}{5} = 108^\circ \] 3. For a decagon (10 sides): \[ \text{Interior angle} = \frac{(10-2) \times 180}{10} = \frac{8 \times 180}{10} = 144^\circ \] So, each interior angle of a dodecagon is \( 150^\circ \), a pentagon is \( 108^\circ \), and a decagon is \( 144^\circ \).