Ответ: 120

[tex]pr = \frac{1}{2} \sqrt{2sp {}^{2} + 2pq {}^{2} - sq {}^{2} } = \frac{1}{2} \sqrt{2 \times 370 {}^{2} + 2 \times 370 {}^{2} - 700 {}^{2} } = 120[/tex]