Answer:
45 old houses
Step-by-step explanation:
new houses : old houses
3 : 9
15 : ?
(3 = 1st ratio and 9 = 2nd ratio)
To find the missing ratio, divide the first ratio from the new ratio:
15 / 3 = 5
Take the product and multiply that by the second ratio to find the missing ratio:
9 x 5 = 45
Answer:
Area of the regular dodecagon inscribed in a circle will be 27 square units.
Step-by-step explanation:
A regular dodecagon is the structure has twelve sides and 12 isosceles triangles inscribed in a circle as shown in the figure attached.
Since angle formed at the center by a polygon = 
Therefore, angle at the center of a dodecagon =
= 30°
Since one of it's vertex is (3, 0) therefore, one side of the triangle formed or radius of the circle = 3 units
Now area of a small triangle = 
where a and b are the sides of the triangle and θ is the angle between them.
Now area of the small triangle = 
= 
Area of dodecagon = 12×area of the small triangle
= 12×
= 27 unit²
Therefore, area of the regular octagon is 27 square unit.
Answer:r=8
Step-by-step explanation: