Area and Perimeter of Triangles and Trapezoids

The perimeter of a figure is the distance around the outside of a figure. To find the perimeter of a figure, add the lengths of all its sides

To find the length of the missing side of the figure, subtract the sum of rest of the sides from the perimeter of the figure

The area of a triangle or a trapezoid can be thought of as half the area of a parallelogram

Area of a triangle = 1/2 (Base) x (Height)

Area of a trapezoid = 1/2 (Sum of the parallel sides) x (Height), or Area = 1/2 (b1 + b2) x h

The Pythagorean Theorem is an equation that relates the sides of a right triangle

The longest side of the triangle is called hypotenuse. The other two sides are called the legs

The sum of the squares of the legs equals the square of the hypotenuse

If the letters a and b represent the lengths of the legs and c the length of the hypotenuse, then a² + b² = c²

To find the area of a figure on the coordinate plane, we first need to plot the figure on the graph

Area of a triangle = 1/2 (Base) x (Height)

Area of a trapezoid = 1/2 (Base1 + Base2) x (Height)

The base and height of a triangle graphed on a coordinate plane can be calculated by counting the number of squares. For example, the base along 6 squares is 6 units long

The area of composite figures can be calculated by adding or subtracting the areas of the various figures (that constitute the figure) accordingly

Area of a rectangle = Length x Width

Area of a triangle = 1/2 (Base) x (Height)