Answer:
a = 24.7 ft
Step-by-step explanation:
We can use the Pythagorean theorem to solve this problem.
a^2 + b^2 = c^2 where a and b are the lengths and c is the hypotenuse
a = the unknown distance fro the building and b is the distance up the wall, and the hypotenuse is the length of the ladder
a^2 + 17^2 = 30^2
a^2 +289 = 900
Subtract 289 from each side
a^2 +289-289 = 900-289
a^2 =611
Take the square root of each side
sqrt(a^2) = sqrt(611)
a = 24.71841419
To the nearest tenth
a = 24.7 ft
