In parallelogram. \( \Large d_{1}^{2} + d_{2}^{2} = 2(l^{2} + b^{2})\) \( \Large d^{2}+(10)^{2} \)=2(64+144) => \( \Large d^{2}=2\times 208-100 \) => \( \Large d^{2} \)=416-100=316 => d=\( \Large \sqrt{316} \) => d=17.76 cm => d > 10