9 cuz 4 times 1/2 is 2 and 2+7=9
Andrew can reach a maximum of
high up the wall.
The right-angled triangle formed can be solved using the
ratio. that is

where
is the distance from the foot of the wall to the tip of the ladder where it rests on the wall. Substituting, and solving for
, we get

Since Andrew can reach an extra
above the point where the ladder rests against the wall, the maximum height Andrew can paint is

Another solved word problem on trigonometry can be found here: brainly.com/question/12146092
Answer:
BC = 1.7
Step-by-step explanation:
Since, cosine of any angle (except right angle) represents the ratio of base length and hypotenuse.
Cosθ = 
From the given right triangle ΔACB,


Cos(70°) 
BC = 5Cos(70°)
= 1.71
≈ 1.7
Step 1: Find a number you can multiply by the bottom of the fraction to make it 10, or 100, or 1000, or any 1 followed by 0s.
Step 2: Multiply both top and bottom by that number.