Sharie makes a canvas frame for a painting using stretcher bars. The rectangular painting will be 12 inches long 9 inches wide. How can she use a ruler to make sure that the corners of the frame will be right angles?
9 and 12 are two sides of a 3-4-5 triangle (9-12-15) with square corners
the diagonal distance is 15 inches
To ensure that the corners of the frame are right angles, Sharie can use the following steps with a ruler:
1. Begin by placing two stretcher bars together to form a corner of the frame.
2. To measure the length of one side of the frame, align the ruler along the length of the stretcher bar. Make sure the ruler is straight and parallel to the stretcher bar.
3. Ensure that the end of the ruler lines up with the desired length of the painting, in this case, 12 inches.
4. Hold the ruler firmly against the stretcher bar and mark the desired length on the stretcher bar using a pencil or a pen.
5. Next, align the ruler along the width of the stretcher bar. Again, make sure the ruler is straight and parallel to the stretcher bar.
6. This time, ensure that the end of the ruler lines up with the desired width of the painting, in this case, 9 inches.
7. Hold the ruler firmly against the stretcher bar and mark the desired width on the stretcher bar using a pencil or a pen.
8. Repeat the above process for the other three sides of the frame, ensuring that the measurements are accurate and aligned with the desired dimensions.
9. Finally, check that the diagonals of the frame (connecting opposite corners) are equal in length. If the diagonals have the same measurement, it confirms that the corners are at right angles.
By following these steps and using a ruler, Sharie can ensure that the corners of the frame will be right angles, providing a sturdy and accurately sized canvas frame for her painting.