Answer:
x= −2 or x=3
Step-by-step explanation:
Since a stop sign is an octagon it has eight sides. So the perimeter will be:
p=8x, p=perimeter and x=side length. We are told that the perimeter is equal to:
16x^2-80x so we can say:
16x^2-80x=8x subtract 8x from both sides
16x^2-88x=0 factor out 8x
8x(2x-11), since we know x>0
x=11/2
x=5.5 units
We are given dimensions of model and actual figure.
model: 9.5cm actual : 30.5m.
We need to find the length of actual shape for the scale factor 5cm.
Let us assume actual length be x m.
Let us set a proportion now.
<h3>5 : x = 9.5 : 30.5</h3>
Let us convert proportion into fractions.
On cross multiplying, we get
9.5x = 5× 30.5
9.5x = 152.5.
On dividing both sides by 9.5, we get
x=16.05.
<h3>Therefore, the scale factor for a model is 5cm= 16.05 m.</h3>
Answer: 423.11 m^2
Step by step explanation:
Area of a circle formula pi*r^2
First solve the area of the big circle
3.14*21^2=1384.74 m^2
Now find the are of the smaller circle
r=21-3.5=17.5
3.14*(17.5)^2=961.63 m^2
Now we can minus the small area off the big area to get the shaded area.
1384.74-961.63=423.11 m^2
So the area of the shaded region is 423.11 m^2
