This Instructional Activity is a part of the Lesson 18, Unit 3, Grade 7. Students examine the meaning of quarter circle and semicircle. Students solve area and perimeter problems for regions made out of rectangles, quarter circles, semicircles, and circles, including solving for unknown lengths when the area or perimeter is given. Students use prior knowledge to find the area of circles, semicircles, and quarter circles and compare their areas to areas of squares and rectangles.