Drawing 3. Figure 3.5. From the radius, r1, of the excircle of the pentagon, now mark off two "a" lengths (labeled "b") to make, r4, the largest concentric circle. Extend the base of the equilateral triangle, FE, to the left and right to intersect this largest circle at points, I, and, H. | back to Geometer's Angle No. 4 |