A 16-ft ladder is placed 4 ft. from the base of a
building. How high on the building will the ladder
reach?

You have a right triangle.

a^2+b^2=c^2

4^2+b^2=256

16+b^2=256

b^2=256-16

b^2=240

b=sqrt240

b=15.49 ft. ans. for the height of the ladder up the wall.

Step-by-step explanation:

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)