Answer: 19.8 ft
Step-by-step explanation:
Use the Pythagorean Theorem formula to solve for how high the top of the ladder reach.
The formula says a^2 + b^2 = c^2
Where a and b are the two legs and C is the hypotenuse.
In this situation, the hypotenuse will be length of the ladder , and either a or b will be the length of the ladder from the building or the length of how long the ladder.
a will be 3 , and c will be 20. Input in the values into the formula and solve for b.
3^2 + b^2 = 20^2
9 + b^2 = 400
-9 -9
b^2 = 391
b =
b = 19.77371 round to the nearest tenth is , 19.8