Area & Similarity Help (1 Viewer)

[Beege]

Can someone tell me how:

* to find the area of a survey diagram
*find the radius of a circle when the area has been given
* Finding the radius of a quadrant having the same area as the sector
* Finding the width of an ellipse when the area and length have been given
* Converting units in similarity

Yeh I just wanna clarify these things for my test on wednesday, would be great help

 

[jyu]

Can someone tell me how:

* to find the area of a survey diagram
*find the radius of a circle when the area has been given
* Finding the radius of a quadrant having the same area as the sector
* Finding the width of an ellipse when the area and length have been given
* Converting units in similarity

Yeh I just wanna clarify these things for my test on wednesday, would be great help

(1) By counting number of unit squares in the region.

(2) r=sqrt(circle area/pi)

(3) r=2*sqrt(sector area/pi) or
r=R*sqrt(2*angle/pi), where R is radius of sector, angle of sector in radians.

(4) w=ellipse area/(pi*L)

(5) Please give an example to show what you meant.

 

[jyu]

(1) By counting number of unit squares in the region.

(2) r=sqrt(circle area/pi)

(3) r=2*sqrt(sector area/pi) or
r=R*sqrt(2*angle/pi), where R is radius of sector, angle of sector in radians.

(4) w=ellipse area/(pi*L)

(5) Please give an example to show what you meant.

Correction to (4)

w=4*ellipse area/(pi*L)