I started by drawing a rectangle from the origin, then dimension the sides 60mm by 70mm. Next, I drew a circle from the midpoint of a side of the rectangle the corner. I trim the circle to form the shape of the object.
After doing so, I drew the other circle with radius 20mm and the smaller rectangle within the main shape. I roughly moved the rectangle to its position and dimension it to size. I dimension the rectangle to its position.
After completing the sketch, I extrude the main shape by selecting the area without the cirle and smaller rectangle.