In one sentence, describe what the following article is about: If the problem tells you the diameter of the circle, it's easy to find the radius. If you are working with an actual circle, measure the diameter by placing a ruler so its edge passes straight through the circle's center, touching the circle on both sides. If you're not sure where the circle center is, put the ruler down across your best guess. Hold the zero mark of the ruler steady against the circle, and slowly move the other end back and forth around the circle's edge. The highest measurement you can find is the diameter. For example, you might have a circle with a diameter of 4 centimeters. A circle's radius is always half the length of its diameter. For example, if the diameter is 4 cm, the radius equals 4 cm 2 = 2 cm. In math formulas, the radius is r and the diameter is d. You might see this step in your textbook as r=d2{\displaystyle r={
rac {d}{2}}}.
Summary: Check the problem for a diameter. Divide the diameter by two.

If small clumps of algae form but do not spread to the rest of the pool, you may have areas of stagnant water. Check that your water jets are functioning properly. They should point into the water at an angle, so the water moves in a spiral pattern. A flocculant or coagulant clumps the algae together, making it possible to vacuum living algae. This may take a hard day of work, but your pool should be clear by the end of it. This is the fastest way to get your pool looking good, but it does not make the water safe to swim in. If algae can multiply, so can viruses and bacteria. Follow this with a chlorine shock treatment to sanitize the pool, and do not swim in the pool until chlorine and pH levels are back to normal. Algaecide will certainly kill your algae, but the side effects and expense may not be worth it. Here are a few factors to weigh when considering this option: Some algaecide products are not powerful enough to treat an existing bloom, especially if you have black algae as well. Ask a pool store employee for help, or find a product with 30%+ active ingredients. Quaternary ammonia algaecides ("poly quats") are cheap, but cause your water to foam. Many people find this annoying. Copper-based algaecides are more effective, but expensive. They usually stain your pool walls as well. After adding the algaecide, wait at least 24 hours before adding other chemicals.
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One-sentence summary -- Improve circulation to handle small spots of algae. Gather the algae with a flocculant. Treat the pool with algaecide.

Q: A moisture meter is a piece of equipment which, when placed directly against a wall, will analyze the moisture content of that wall. If you know that you have a leak within a certain wall, but are unaware of the precise location, place the moisture meter at 5 or 6 different spots on the wall. Whichever spot gives the highest moisture reading is closest to the leak. You can purchase or rent a moisture meter at a large hardware store or home-improvement store. These gadgets are frequently used by professional home-inspectors to find leaks or wet walls. Infrared cameras detect heat, and can indicate the temperature of a wall. A leaky, wet wall will have a cooler temperature than the surrounding wall. Train an infrared camera on a wall with a leak, and look to see which section of the wall is the coldest. This will be the section of the wall nearest the leak. When using an infrared camera, hot objects will have red or orange coloring, while cool objects will have blue or purple coloring. You may be able to rent an infrared camera from a professional contractor, a home-improvement center, or from a photography shop. Use a utility knife to score a line about 10 inches (25cm) long into your drywall at the location where you see visible signs of a water leak (mold, discolored drywall, etc.). Then, using a drywall saw, cut along the line you just scored. Cut a hole in the wall large enough for your head to fit inside. Stick your head in the wall and look around until you spot the source of your leak. Enlarge the hole so that you can also insert a flashlight to see better inside the wall, if needed. Often, the patch of wall which shows signs of a leak is not directly in front of the leaky pipe or fixture. Water can drain along the outside of pipes in your walls or trickle many feet down the inside of your walls before the telltale signs of a leak become visible. Both a utility knife and a drywall saw can be purchased at your local hardware store.
A: Scan for moisture inside walls with a moisture meter. Find the cold, leaky part of a wall with an infrared camera. Cut into your drywall to find the source of a leak.

Problem: Article: For quick counting, the first thing you should do is create a stack of all of your 1s, all of your 5s, all of your 10s, all of your 20s, and so on. Gather all of your bills into one big stack and then go through it one bill at a time and put each one in the stack with its respective denomination. Do this while or after you separate your bills into different stacks. This may make counting faster and easier, and also keeps your money more organized. Pick up one stack and hold it in your nondominant hand. Grab the top bill with your dominant thumb and pointer finger to make sure it's only 1 bill. Then place the bill down on a flat surface in front of you while you count it. Continue to grab and move the bills one at a time while counting by the denomination. For example, if you're counting a stack of 5 dollar bills, think or say "5, 10, 15, 20," as you grab and place the first 4 bills onto the flat surface. Secure and set aside each stack of 50 bills of the same denomination. This is easy if you're counting 1s, because you'll just stop once you've reached 50. It's helpful to know the monetary value of 50 of each denomination beforehand so that you know when to stop. If you're counting 5 dollar bills, stop when you get to $250. If you're counting 10 dollar bills, stop when you get to $500. If you're counting 20 dollar bills, stop when you get to $1,000. Continue banding each stack of 50 bills and setting them aside. Once you're out of bills, add each stack together starting with the higher denominations and then add any leftover bills afterward. It may be easier and faster to use a calculator at this point. For example, if you have 3 stacks of 20s, 2 stacks of 10s, 5 stacks of 5s and 23 loose 1 dollar bills, your math would look like this: 1,000 + 1,000 + 1,000 + 500 + 500 + 250 + 250 + 250 + 250 + 250 + 23 = 5,273.
Summary:
Separate your stacks by denomination. Adjust the bills so that they're all facing the same direction. Count each bill as you pass it from one hand to the other. Wrap a rubber band around a stack once you reach 50 bills. Add up all banded stacks and leftover bills.