Perimeter of Shapes With Semicircle Edges

Start with the area sheets, then move to perimeter, where the straight sides have to be added in. Save the composite figures for last, since they combine area of a polygon and area of a curve.

Find perimeters of shapes with semicircle edges by adding straight edges to curves, skipping dashed lines. The directions on the page read: Add the straight outer edges and the curved edges to find the perimeter P. Each curve is half of πd. Use 3.14 for π. Dashed lines do not count. Show your work in the box. An answer key is included.

Yes, both. We made it for 7th grade geometry, and it works the same at home or at school. At home, a student can work through it alone and then go over it with you, which shows quickly what is solid and what needs another look. In class it works as independent practice, homework or a warm-up, and you can print one copy or a full set.

Find the area of the whole circle with A = πr², then divide by 2. If a diameter is given, halve it to find r first. Area of Semicircles From Diameters practices this and rounds to the nearest hundredth.

Add the curved part, which is half of πd, to the straight side, which is the diameter d. For d = 10 cm, the curve is about 15.7 cm and the perimeter is about 25.7 cm. Perimeter of Semicircles From Diameters sets this up in boxes.

Find πr² and divide by 4. Area of Quarter Circles in Terms of Pi leaves π in the answer, and Area of Quarter Circles From Radius uses 3.14.

Find the area of the rectangle or triangle and the area of the semicircle, then add them if the curve sticks out or subtract if it is cut out. Composite Figures With Semicircles gives a rectangle, semicircle and total box for each figure.