Q&A for How to Find the Perimeter of a Polygon

First, create a plan for doing the homework and build in breaks or rewards. For example, get one task done and then set a reward for yourself to take a 15-minute break to call a friend or to go outside for a walk.

Build a positive reinforcement loop for yourself by having a plan. For example, take the test day and then work backwards from that and decide what things you need to get done during the time you have. Then work towards those things. It's putting one foot in front of the other. It's also being realistic. If you realize the plan is not possible, but you'll still get through about 80% of it, you're still going to probably do okay in the class. You've done the best that you can. It takes this weight off of your shoulders of having to be perfect. Instead, it's I have to do the best that I can in any given circumstance and that's all I can do.

To find the perimeter, add up the lengths of all the sides of the polygon. Finding the area can be a little more complicated, since it depends on what kind of shape you’re dealing with. To calculate the area of a regular polygon, multiply ½ x p (the perimeter) x a (the apothem, or the distance from the center of the polygon to the midpoint of any side). If the polygon is irregular, you’ll need to divide it up into regular shapes (e.g., a rectangle and a triangle), find the area of each part, and add them together.

As long as it’s made up of straight lines, finding the perimeter is as simple as adding up the lengths of all the sides. If there are curves involved, it can get a bit more complex! For instance, if your shape is made up of 3 straight sides and a semicircle, you’d need to add the 3 straight sides plus the arc length of the curved side (in the case of a semicircle, .5 x π x diameter of the semicircle).

It depends on the kind of shape you’re dealing with. If the polygon is all right angles, you can easily use the known lengths of the other sides to figure out the length of the missing side. If there are non-right angles, break down the shape into right-angled triangles and use the Pythagorean theorem (a^2+b^2=c^2) to solve for the missing lengths.

The four consecutive odd integers just below 15 are 7, 9, 11 and 13, so the perimeter is 7 + 9 + 11 + 13 + 15 = 55.

Add the five lengths together.

12.7 + 8 + 11.4 + 7.3 = 39.4.

The area of a regular octagon is equal to the square of the side, multiplied by 4.828. A = (4.828)(a²). Therefore, a² = A / 4.828, and a = √(A/4.828) = √(.207)(A). Use 55 for A, and calculate a.

The area formula for a regular hexagon is [(3√3) / 2] s², where s is the length of a side. So in this case it's (2.598)(10)² = 259.8 square centimeters.

Multiply 90 cm by 5.

Are the angles given? If they are you can split the polygon into triangles and use the sine and cosine rules to find the sides.

The first perimeter is 5 + 3 + 7 + 10 + 12 = 37 cm. The ratio of the first perimeter to the second perimeter is 37:148. The ratio of the first polygon's smallest side to the second polygon's smallest side is also 37:148. Let x be the length of the second polygon's smallest side. Then 3 / x = 37 / 148. By cross-multiplying, 37x = 444. So x = 12 cm.

If each of the ten sides measures 33 inches, the perimeter is 10 x 33 = 330 inches.

As your question is posed, the perimeter cannot be found. You would have to know some angles.