You will not put carpeting under the couch. You need to carpet the area around your blue couch. Your backyard is 125 feet wide and 90 feet long. You need to find enough grass seed to cover your backyard. Using the distance formula we can find the perimeter.įrom point B to C is the base of the triangle and we haveĪC + AB + BC = 5 + 6.32 + 6.71 ≈ 18.03 cmġ. This is a system in centimeters.įirst let’s draw the points on the coordinate system. In simple problems the height will be given to you, but you will sometimes need to use the given data to calculate it.įind the area and perimeter of a triangle circumscribed by the following coordinate points: A(6, 8), B(8, 2), and C(3, 2). You can also find its area by using the following formula: The area of a triangle is found by using the base and the height of the triangle. The perimeter of a triangle is found in the same way as the other plane figures – by adding up the sum of the length of its sides. The area of a circle is found by using the following formula:įind the circumference and area of a circle of diameter 60 cm.Ī = πr 2 = π(30) 2 = 900 π cm 2 ≈ 2827.4 cm 2įinding the Perimeter and Area of a Triangle Pi is an irrational, unit-less number which equals Where r is the radius, d is the diameter and π is the value known as 'pi,' which is the ratio of the diameter of the circle to its circumference. The formula to find the circumference of a circle equals The length of that line will be the circumference.

Imagine that yo u can cut t his circle at one point and stretch it out into a line.

The circumference of a circle is the perimeter of the circle. So, we can say that the diameter of a circle is twice the radius. Note that the line needs to pass through the cen ter of the circle in order to be the diameter. The distance from a point on the circle to a point on the opposi te side is known as the diameter. This distance from the center is known as the radius of the circle. To find the perimeter and area for a square, we adjust the rectangle formu las:įind the perimeter and area of a square of length 40 cm:įinding the Circumference and Area of a CircleĪ circle is a figure where all the points along the sides of the figure are the same distance from the center. It is a rectangle in which the length and the width are equal to each other. For a rectangle the area is measured using the following formula:įind the perimeter and area of a rectangle with a length of 50 cm and a width of 32 cm.įinding the Perimeter and Area of a SquareĪ square is another quadrilateral (four-sided figure). It is measured in square units (m 2, km 2, in 2, ft 2 …). So, the perimeter can be found by using this formula:Īrea is the total surface that a two dimensional figure covers. In this case we can see that the rectangle has two sets of sides, two for length and two for width. Perimeter is the sum of the length of al l the sides of the figure. To find the perimeter and area of a rectangle, we use the length of the long side and short side of the rectangle, usually called the length and width. You will also be able to find the circumference and area of circles.įinding the Perimeter and Area of a Rectangle Choosing outer_radius = max(width, height) * 0.5Īs the radius for the outer circle is obviously not enough.The formulas in this lesson will help you find the perimeter and area of squares, triangles, and rectangles. In other words, the bounding rectangle width,height must fit entirely into the outer circle. There shall be no empty areas in the corners, the area shall be completely covered by the circle.

How should I choose the radius of the outer circle to make sure that the outer circle will entirely fill my bounding rectangle defined by width*height.

My current parameters are the following: A) inner circle (start of gradient)Ĭenter pointer of inner circle: (width*0.5|height*0.5)Ĭenter pointer of outer circle: (width*0.5|height*0.5) Now my question, how should I choose the radius of the outer circle? I'd like the radial gradient to fill a rectangular area defined by 'width' and 'height' completely. The pixman image library can draw radial color gradients between two circles.

Area in math circles in rectangle