Perimeter Rectangles Squares and Triangles Perimeter n Measures

Perimeter Rectangles, Squares, and Triangles

Perimeter n Measures the distance around the edge of any flat object. n To find the perimeter of any figure, ADD the lengths of its sides.

What is a rectangle? A rectangle has: § 4 sides § 4 square corners or right angles § Opposite sides are of equal lengths § Opposite sides are directly across from each other

To find the perimeter of a rectangle: 18 15 Use the formula P= 2 x length + 2 x width P= 2 x 18 + 2 x 15 P= 36 + 30= 66 Or ……. You can always add the sides. P= 18 +15 +15= 66

What is a square? A square has: 4 equal sides n 4 right angles n

To find the perimeter of a square: Use the formula: 3 3 n. P = 4 x side n P = 4 x 3 = 12 Or. . You can add the sides. P = 3 + 3 + 3 = 12

What is a triangle? n A triangle has 3 sides. All triangles may not look the same, but they all have 3 sides.

To find the perimeter of a triangle: Use the formula: n. P = side + side n P = 6 + 4 = 16 6 6 4

Circumference of a Circle n The perimeter, or the distance around a circle, is called the circumference.

Circumference of a Circle n To find the circumference of a circle, you need to know either the diameter or radius of the circle.

The diameter of a circle is a line segment drawn through the center of the circle with endpoints on the circle. Diameter

n The radius is a line segment connecting the circle’s center to a point on the circle. The length of the radius is one-half the length of the diameter. Radius Diameter

The formula for finding circumference (C) is C = pi x diameter. n The value of pi is about 3. 14, so the formula for finding the circumference of a circle is C = 3. 14 x diameter.

Find the circumference of the circle. n. C = pi x diameter n C = 3. 14 x 4= 12. 56 4