A tall building casts a shadow of 20 meters. John, who is 1.5 meters tall, casts a shadow of 10 cm. how tall is the building?

h/20 = 1.5/0.1

150 cm /10 cm = x/2000 cm

cross multiply to get x

10x = (150)(2000)
divide by 10 to find answer in cm.

change to meters by dividing by 100.

To find the height of the building, we can use proportions.

Let's set up a proportion between the height of the building and the length of its shadow, as well as the height of John and the length of his shadow.

Height of building / Length of building's shadow = Height of John / Length of John's shadow

We know that the height of John is 1.5 meters and the length of his shadow is 10 cm.

Plugging in these values:

Height of building / 20 meters = 1.5 meters / 10 cm

To make the units consistent, we need to convert 10 cm to meters. Since 1 meter is equal to 100 centimeters, we divide 10 cm by 100:

1.5 meters / (10 cm / 100 cm) = Height of building / 20 meters

Simplifying the equation:

1.5 meters / 0.1 meters = Height of building / 20 meters

This gives us:

15 = Height of building / 20

To solve for the height of the building, we can cross multiply:

15 * 20 = Height of building

Height of building = 300 meters

Therefore, the height of the building is 300 meters.