Daniel runs 225 km in a charity fun run. Sandra runs 8,420 m less. How far does Sandra run?

216.58 kilometers

8420 m to km is 8.42 km so 225 km - 8.42= 216.58 km

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6