4.3. Triangle Congruence using SSS and SAS http://www.ck12.org
SSS Postulate of Triangle Congruence
Consider the question: If I have three lengths, 3 in, 4 in, and 5 in, can I construct more than one triangle with these
measurements? In other words, can I construct two different triangles with these same three lengths?
Investigation 4-2: Constructing a Triangle Given Three Sides
Tools Needed: compass, pencil, ruler, and paper
- Draw the longest side (5 in) horizontally, halfway down the page.The drawings in this investigation are to
scale. - Take the compass and, using the ruler, widen the compass to measure 4 in, the next side.
- Using the measurement from Step 2, place the pointer of the compass on the left endpoint of the side drawn
in Step 1. Draw an arc mark above the line segment. - Repeat Step 2 with the last measurement, 3 in. Then, place the pointer of the compass on the right endpoint
of the side drawn in Step 1. Draw an arc mark above the line segment. Make sure it intersects the arc mark
drawn in Step 3.