Bus length =√(H? +R？ )=√(5? +5? )=5√2,

The side is fan-shaped,

Sector radius = bus length =5√2,

The arc length of the sector = the circumference of the cone bottom =2×π×R=2π×5= 10π,

Sector area = sector radius × arc length /2=5√2× 10π/2=25(√2)π,

Bottom area =R? ×π=5? π=25π

Surface area of cone = side area+bottom area.

=25(√2)π+25π

=25π(√2+ 1)