to find out the area of a rectangle or a square you have to multiply the length by the width of it. to find out the area of a triangle you have to divide the length by breath and half it.
to find out the area of a shape like a shape of the L letter, you have to separate the shape into squares,rectangles and triangles. like in the picture, i have separated the L shape into two rectangles you should find the area of each rectangle and add them together to get the whole area of the shape.
