Question

Mary places a 15-foot ladder against her house. The base of the ladder is 3 feet from her house How high up to the nearest tenth of a foot, the ladder reach on Mary's house?

taking math test plz help

Answer 1

Answer:

Let the base of the 15ft long ladder be placed x ft away from the wall so that it exactly reaches the top of a 12- foot tall wall.

By Pythagorean theorem

12

2

+

x

2

=

15

2

⇒

x

2

=

15

2

−

12

2

=

81

⇒

x

=

√

81

=

9

ft