Respuesta :
using the Pythagoras theorem,
21²=4²+height²
441=16+height²
425=height²
height=√425=20.6
The ladder reaches a height of 20.6 ft on the building.
21²=4²+height²
441=16+height²
425=height²
height=√425=20.6
The ladder reaches a height of 20.6 ft on the building.