How many centimeters is the diagonal of 80 cm square tile?

How many centimeters is the diagonal of 80 cm square tile?

80√2,

There are a number of floor tiles of the same specifications, 60 cm long and 45 cm wide, which need to be paved into a square floor. At least how many such tiles should be used

The least common multiple of 60 and 45 is 180
180/60=3
180/45=4
To lay a square floor, you need 4x3 = 12 bricks

As shown in the figure, four identical rectangular floor tiles and a square with a side length of 60cm are turned into a large square with a variable length of 80cm
My reward is not enough=

The width of the rectangle is 10 cm and the length is 70 cm