Resources for Area of Rectangles, Triangles and Parallelograms
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Questions
10
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Video Tutorials
1
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Area of Rectangles, Triangles and Parallelograms Theory
![Area of a rectangle with length (L) and base length (B) is given by the formula $$ A=L B \text {. } $$ Area of a triangle with height \((H)\) and base length \((B)\) is given by the formula $$ A=\frac{1}{2} B H \text {. } $$ The area of a parallelogram with height \((H)\) and base length (\(B\)) is given by the formula. $$ A=B H . $$ \begin{multicols}{2} \textbf{Example 1}\\ \textbf{i)} Find the area of a rectangle with length \(3 \text{~cm}\) and base length \(5 \text{~cm}\).\\ \textbf{ii)} Find the area of a triangle with height \(8 \text{~cm}\) and base length \(5 \text{~cm}\).\\ \textbf{Example 1 solution}\\ \textbf{i)} \(\begin{aligned}[t] A & =L B \\ & =3 \times 5 \\ & =15 \text{~cm}^2 \end{aligned}\)\\[4pt] \textbf{ii)} \(\begin{aligned}[t] A & =\frac{1}{2} BH \\ & =\frac{1}{2} \times 5 \times 8 \\ & =\frac{1}{2} \times 8 \times 5 \\ & =4 \times 5 \\ & =20 \text{~cm}^2 \end{aligned}\) \columnbreak \textbf{Example 2}\\ \textbf{i)} Find the area of a parallelogram with height \(7 \text{~cm}\) and base length \(6 \text{~cm}\).\\ \textbf{ii)} A parallelogram has an area of \(48 \text{~cm}^2\), its height is \(6 \text{~cm}\). Find the length of its base.\\ \textbf{Example 2 solution}\\ \textbf{i)} \(\begin{aligned}[t] A & =BH \\ A & =6 \times 7 \\ & =42 \text{~cm}^2 \end{aligned}\)\\[3pt] \textbf{ii)} \(\begin{aligned}[t] A & =B H \\ 48 & =B \times 6 \\ 6 B & =48 \\ B & =48 \div 6 \\ B & =8 \text{~cm} .\end{aligned}\) \end{multicols}](/media/ij3d11qg/7955.png)