The area of a rectangle can be found by multiplying its length by its width, [math]A=l\cdot w[/math].[br][list=1][*][math]A=5\cdot6=30[/math] units[sup]2[/sup][/*][*][math]A=7\cdot3=21[/math] units[sup]2[/sup][/*][*][math]A=3\cdot3=3^2=9[/math] units[sup]2[/sup][/*][/list]The area of a square can also be found by using [math]A=l\cdot w[/math]. However, the length and the width are the same for a square, [math]l=w[/math]. Therefore, the area equation can be simplified to just [math]A=l^2[/math].

The area of a right triangle can be found by taking half of the area of a rectangle (or square), [math]A=\frac{1}{2}\left(l\cdot w\right)[/math].[br][list=1][*][math]A=\frac{1}{2}\left(5\cdot6\right)=\frac{1}{2}\left(30\right)=15[/math] units[sup]2[/sup][/*][*][math]A=\frac{1}{2}\left(7\cdot3\right)=\frac{1}{2}\left(21\right)=10.5[/math] units[sup]2[/sup][br][/*][*][sup][math]A=\frac{1}{2}\left(3\cdot3\right)=\frac{1}{2}\left(3^2\right)=\frac{1}{2}\left(9\right)=4.5[/math] [/sup]units[sup]2[/sup][/*][/list][size=100][b][color=#1e84cc]Bonus:[/color][/b] The area of a right triangle can be found by taking half of the multiplication of the lengths of the [color=#6aa84f][b]legs[/b][/color], [math]A=\frac{1}{2}\left(l_1\cdot l_2\right)[/math][/size].

Both shapes are composed of squares ([math]A=l^2[/math]) and right triangles ([math]A=\frac{1}{2}\left(l\cdot w\right)[/math]).[br][list=1][*][math]A=7^2+\frac{1}{2}\left(7\cdot5\right)=49+\frac{1}{2}\left(35\right)=49+17.5=66.5[/math] units[sup]2[/sup] (1 square + 1 right triangle)[/*][*][math]A=6^2+2\left[\frac{1}{2}\left(5\cdot7\right)\right]=36+5\cdot7=36+35=71[/math][sup] [/sup]units[sup]2[/sup] (1 square + 2 same right triangles)[/*][/list]

Both shapes are composed of squares ([math]A=l^2[/math]) and right triangles ([math]A=\frac{1}{2}\left(l\cdot w\right)[/math]).[br][list=1][*][math]A=10^2-4^2=100-16=84[/math] units[sup]2[/sup] (1 big square - 1 little square)[/*][*][math]A=3\left[\frac{1}{2}\left(6\cdot6\right)\right]=3\left[\frac{1}{2}\left(36\right)\right]=3\left[18\right]=54[/math][sup] [/sup]units[sup]2[/sup] (3 same right triangles) [b][u]OR[/u][/b] [math]A=12^2-3\left[\frac{1}{2}\left(6^2\right)\right]-6^2=144-3\left[\frac{1}{2}\left(36\right)\right]-36=144-3\left[18\right]-36=144-54-36=54[/math] units[sup]2[/sup] (1 big square - 3 same triangles - 1 little square)[/*][/list]