Answer:
Step-by-step explanation:
D²=290²+2030²
=290²+(290×7)²
=290²+290²×7²
=290²(1+7²)
=290²(1+49)
=290²×50
=290²×25×2
=290²×5²×2
D=290×5×√2
D=1450√2
