The 3-4-5 Technique

Pull a tape measure along the first wall out to the distance of the length of the wall. For example, if your **four posts** will be set 10 feet apart along the length and width of the building, then hook the tape measure to the first stake and pull it out 10 feet, placing a stake at 10 feet.

Also Know, what is the 345 rule? The Pythagorean theorem states that the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides. This is shown as A squared + B squared = C squared and is known as the **3-4-5 rule** in construction.

Subsequently, question is, what is the 3 4 5 Triangle rule?

The **3**:**4**:**5 triangle** is the best way I know to determine with absolutely certainty that an angle is 90 degrees. This **rule** says that if one side of a **triangle** measures **3** and the adjacent side measures **4**, then the diagonal between those two points must measure **5** in order for it to be a right **triangle**.

How do you square a fraction?

To **square a fraction**, simplify the **fraction** as much as you can. Next, multiply the numerator by itself, then multiply the denominator by itself. If you are squaring a negative **fraction**, the result will be positive. Reduce the **fraction** to its simplest form.

### How do you determine a square corner?

Measure the distance between your marks. If the distance is 5 units, your corner is square. If the distance is less than 5 units, your corner is less than 90º. Move the sides apart. If the distance is over 5 units, your corner has a measurement of more than 90º.

### What happens if deck is out of square?

Cut a miter or angle on the end on the deck boards if needed. If the ends of the deck are not square, the deck boards may not fit right, or they won’t look right. Depending on how much the deck is out-of-square, both ends of the deck boards may need to be cut with different miter angles.

### How do you hide out of a square deck?

Another way to hide the out of square joists would be to run the deck boards parallel with the back of the house, as I’m sure you plan to, let the boards cantilever past the joists on both ends as previuosly mentioned, and use clips to attach the deck boards.

### How do I calculate decking squared?

To find this multiply the width of the floor-board in feet times the length in feet. You can use our feet and inches calculator to convert the board width in inches to feet. To find the number of boards you need, divide the total deck square footage by the board square footage, eg. total ft2 / board ft2.

### How do you jack up a deck?

How to Jack Up a Deck Access the area under the deck. Place a short length of two-by-four lumber on the ground beside the support post as support for the jack. Position a car jack on the two-by-four or use a bottle jack. Raise the jack so it contacts the wooden floor joist supporting the decking.