290 + 80 = 370
576.
40+30+20+80=170
The estimate of a circle with a circumference of 288 is a circle with a diameter of 91.67
It is: 288+29929 = 30217
307 + 288 = 595
1,042
79 + 79 = 158
Sum = 79*(79+1)/2 = 79*80/2 = 3160
a + 79
79 + 79 = 158
79 + 79 = 158 / 2 = 79.
79