1. **Problem statement:** We have a six-pointed star made of equal line segments. Each angle marked with a plus (+) is 70°. We need to find the size of each angle marked with a circle (o). 2. **Understanding the star and angles:** The star is symmetric and formed by equal line segments. At each vertex where the plus (+) and circle (o) angles meet, the angles around that point sum to 360° because they form a full circle. 3. **Key insight:** Each vertex of the star has one plus angle and one circle angle adjacent to each other along the star's outline. Since the star is made of equal segments and symmetric, the sum of the plus and circle angles at each vertex is 180° because they form a straight line (linear pair). 4. **Using the linear pair rule:** $$\text{plus angle} + \text{circle angle} = 180^\circ$$ 5. **Substitute the given plus angle:** $$70^\circ + o = 180^\circ$$ 6. **Solve for the circle angle $o$:** $$o = 180^\circ - 70^\circ$$ $$o = 110^\circ$$ 7. **Answer:** Each angle marked with a circle (o) is $110^\circ$.