Answer:
Step-by-step explanation:
Given
Fireplace is in the form of semi-ellipse with height of 3 ft from center
Length of base=8 ft
if the arch is in the form of ellipse then it can be considered as horizontal ellipse with 2 a and 2 b be length of major and minor axis
2 a =8
a=4 ft
If contractor cover the whole base
then total length of string=2a =8 ft
(b)String should be nailed at focus
focus of ellipse is a e
where e=eccentricity
Focus 
Thus string should be nailed at 2.64 m from center
P 140 units
A 1200 units^2
Step-by-step explanation:
The length of the rectangle is 20 to -20 = 20 - -20 = 40 units
The width of the rectangle is 20 to -10 = 20 - -10 = 30 units
The perimeter is given by
P = 2 ( l+w) = 2 (40+30) = 2 (70) = 140 units
The area is given by
A = lw = 40*30 = 1200 units^2
Answer:
In two similar triangles, the ratio of their areas is the square of the ratio of their sides. Try this The two triangles below are similar. Drag any orange dot at P,Q,R. Note the ratio of the two corresponding sides and the ratio of the areas.
Step-by-step explanation:
