item20
BasicMathSkills AddSubtractDecimals InverseOperations
ComplementarySupplementary MultiplyDecimals NumberProperties
item8 Exponents OrderofOperations-GEMA1
VerticalAngles FactorTrees item3
AreaofPolygons Fractions ProportionsRatios
AreaofParallelogram AddSubtractFractions Quadrilaterals1
AreaofRectangle multiplyfractions RationalNumbers
AreaofSquare dividefractions SieveofEratosthenes
AreaofTrapezoid lowesttermsfractions
AreaofTriangle mixednumbers
Homework1
BezierCurves
item22
CirclesandPi Integers ClassNews
Circumference AddSubtractIntegers item24
AreaofCircle MultiplyDivideIntegers item17
Finding the Area of a

©2009–2016 Sherry Skipper Spurgeon.

All Rights Reserved.

Let's check out rectangles. Now, rectangles, like squares, are parallelograms with adjacent sides meeting at perpendicular lines. These perpendicular sides provides us with a height, thus a need for some new variables.

Here's a rectangle and we'll call the shorter sides the height (measure of 4 cm) and the longer sides the base (measure of 6 cm).

arearectangle

Look at the rectangle. With the little square tiles, it is easy to count the area but, given the base and the height, what formula do you think you could use instead?

The capital A indicates 'Area' and the little sub-script R indicates the shape 'Rectangle.'

Did you come up with…

then, by using the Substitution Property with 6 for the b and 4 for the h come up with…

item45

Look for the right angle symbol. This will give you the base and the height (in other words, the numbers you need to use!)

Challenge: What's the area of the rectangle below? You can do it!

rectangleforarea

Remember: Since the cm is also squared, the units will be 'square units.'

lemonsqueezy

Easy-peasy, lemon-squeasy!

item48
b stands for base and
h = 4 cm
b = 6 cm