Mathematics, Geometry, Problem Solving

Grade 5- 8

Objective

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

Directions

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 r²).
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 r² 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.

Resources

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