Plane Areas

08 Area Enclosed by r = a sin 3θ and r = a cos 3θ

Problem
Find the area bounded by $r = a \sin 3\theta$ and $r = a \cos 3\theta$.
 

008-polar-area-three-leaf_rose_sine_cosine.gif

 

05 Area Enclosed by r = a sin 2θ and r = a cos 2θ

Problem
Find the area bounded by $r = a \sin 2\theta$ and $r = a \cos 2\theta$.
 

008-polar-area-four-leaf_sine_cosine.gif

 

01 Area Enclosed by r = 2a cos^2 θ

Problem
Find the area enclosed by r = 2a cos2 θ.
 

004-polar-area-two-leaf-rose-integration.gif

 

07 Area Enclosed by r = 2a cos θ and r = 2a sin θ

Problem
Find the area enclosed by the following:

(a)   $r = 2a \cos \theta$
(b)   $r = 2a \sin \theta$

 

001-polar-area-circle_01.gif

 

Example 8 | Area bounded by arcs of quarter circles

Problem
Arcs of quarter circles are drawn inside the square. The center of each circle is at each corner of the square. If the radius of each arc is equal to 20 cm and the sides of the square are also 20 cm. Find the area common to the four circular quadrants. See figure below.
 

018-arcs-of-quarter-circles-common-area.gif

 

Example 7 | Area inside the square not common to the quarter circles

Problem
The figure shown below is composed of arc of circles with centers at each corner of the square 20 cm by 20 cm. Find the area inside the square but outside the region commonly bounded by the quarter circles. The required area is shaded as shown in the figure below.
 

06 Area Within the Curve r^2 = 16 cos θ

Example 6
What is the area within the curve r2 = 16 cos θ?