UK Secondary (7-11) Area
Lesson

Let's review the rules for areas of quadrilaterals, triangles and circles that we have covered so far.

Areas Rectangle $\text{Area of a Rectangle }=\text{length }\times\text{width }$Area of a Rectangle =length ×width $A=L\times W$A=L×W Square $\text{Area of a Square}=side\times side$Area of a Square=side×side $A=S\times S$A=S×S $A=S^2$A=S2 Triangle $\text{Area of a triangle }=\text{half of the area of the rectangle with base and height the same as triangle }$Area of a triangle =half of the area of the rectangle with base and height the same as triangle $\text{Area of a triangle }=\frac{1}{2}\times\text{base }\times\text{height }$Area of a triangle =12​×base ×height $A=\frac{1}{2}bh$A=12​bh Parallelogram $\text{Area of a Parallelogram }=\text{Base }\times\text{Height }$Area of a Parallelogram =Base ×Height $A=b\times h$A=b×h Trapezium $\text{Area of a Trapezium}=\frac{1}{2}\times\left(\text{Base 1 }+\text{Base 2 }\right)\times\text{Height }$Area of a Trapezium=12​×(Base 1 +Base 2 )×Height $A=\frac{1}{2}\times\left(a+b\right)\times h$A=12​×(a+b)×h Kite $\text{Area of a Kite}=\frac{1}{2}\times\text{diagonal 1}\times\text{diagonal 2}$Area of a Kite=12​×diagonal 1×diagonal 2 $A=\frac{1}{2}\times x\times y$A=12​×x×y Rhombus $\text{Area of a Rhombus }=\frac{1}{2}\times\text{diagonal 1}\times\text{diagonal 2}$Area of a Rhombus =12​×diagonal 1×diagonal 2 $A=\frac{1}{2}\times x\times y$A=12​×x×y Circle $\text{Area of a circle}=\pi r^2$Area of a circle=πr2

#### Worked Examples

##### QUESTION 1

Find the area of the rectangle shown. ##### QUESTION 2

Find the area of the parallelogram shown. ##### QUESTION 3

Find the shaded area shown in the figure. 