Calculate the area of the plane figure surrounded by the following curves, r = 2cos θ and R = 2 (1-cos θ) It's the area enclosed by them, not the area enclosed by each other I want to know what these two figures are. Is the second inverted cardioid? What is the first? In fact, it seems that you can make graphics

Calculate the area of the plane figure surrounded by the following curves, r = 2cos θ and R = 2 (1-cos θ) It's the area enclosed by them, not the area enclosed by each other I want to know what these two figures are. Is the second inverted cardioid? What is the first? In fact, it seems that you can make graphics

This is the polar equation
The first one: R ^ 2 = 2rcos θ, i.e. x ^ 2 + y ^ 2 = 2x, is a circle
The second is the heart line

Xiao Ming wants to encircle the city with iron wire. If he wants to make the triangle area 30 square meters, how long is the iron wire? Just list the equation
Xiao Ming wants to use iron wire to encircle an equilateral triangle shelf. If he wants to make the triangle area of the encircled city 30 square meters, how long is the iron wire? Just list the equation, not the upper trigonometric function

Let the side length of an equilateral triangle be a, and the area of an equilateral triangle be 3 times the square of A
Just list the equation
I don't know,

Xiao Ming wants to use iron wire to encircle an equilateral triangle shelf. If he wants to make the enclosed triangle area 30 square centimeters, how long does it need?

If the base length of a triangle is a,
Then the area of the triangle is three times the area of the root of the fourth
Can be used as a conclusion to remember, very useful drop ~)
That's it~

A circle is a plane figure surrounded by (). In the same circle, all radii are ()

A curve