Mathematics, Geometry, Problem Solving

Grade 5- 8

Students will learn how to use basic geometry to solve word problems

**Perimeter**

Perimeter is the length around a closed shape. It is computed by adding the length of all the sides of the figure. The formula for finding the perimeter of rectangles and other parallelograms is P = (l + w) x 2 or P = 2 l + 2 w

**Area**

The area of a flat surface is a measure of how much space is covered by that surface. Area is measured in square units.

**Area of a Rectangle**

The area of a rectangle is computed by multiplying the width of one side times the length of the adjoining side (A = l x w). The area of a rectangle can also be determined by multiplying the base times the height (A = b x h).

**Area of a Triangle**

A triangle is always one half of a rectangle or a parallelogram. The area of a triangle is computed by multiplying 1/2 of the base times the height of a triangle (A = 1-2 b x h)

**Area of a Parallelogram**

The area of a parallelogram is computed by multiplying the base times the height (A = b x h).

**Area of a Circle**

To find the area of a circle, multiply π (3.14) times the radius times the radius again (A = π r^{2}).

**Circumference **

The circumference is the distance around a circle. To find the circumference of a circle, multiply π (which always equals 3.14) times the diameter or multiply 2 times π (3.14) times the radius (C = π d or C = 2 π r).

**Volume**

The formula for finding the volume of a rectangular prism, such as a box, is to multiply the length times the width times the height (V = l x w x h).

The formula for finding the volume of a cylinder is to multiply π (3.14) times the radius squared times the height (V = π x r^{2} x h ).

Volume is always computed in cubic units. Use cubic inches or centimeters when determining volume for small prisms and cylinders, and cubic feet or meters for larger ones.

- copies of the activity sheets (see the link below)