Circle Proofs Worksheets

Tips When Writing Circle Proofs - Circles are defined as the set of all the points that lie equidistant from a distance r, known as the radius. In geometry, we say that all circles are similar, that means that we can take one circle, alter it to match up with the other one. We take the smaller circle and move it to a point where its center coincides with the bigger circle. Or, we can take the smaller circle, enlarge it until its radius is the same as the bigger circle. Suppose we have to prove that angle subtended at the circumference by a semicircle is a right angle. First, we will create a problem statement. Draw a circle and marks its diameter and center using the diameter of the circle, draw the two sides of the triangle and extend them to meet at the vertex. Next, draw a radius from the vertex to the center and split the triangle. The two triangles will have two sides of the same length, and hence these are the isosceles triangles. Also, these isosceles triangles will have two angles of the same measurements. Lastly, we will add up the angle to find that their sum is equal to 180 degrees.