This is called the exterior angle property of a triangle. The total angle at a point is 360 ° w +x+y+z=3600 2. Two angles are said to be Co-exterior angles if they are exterior angles and lies on same side of the transversal. ... FOM 11 2.3 Angle Properties In Triangles The sum of the angles in a triangle is 180 °°°°. The total angle on a straight line is 180 ° In the diagram, x+y+z=1800 3. The Consecutive Interior Angles Theorem states that if two parallel lines are cut by a transversal, then each pair of alternate interior angles is congruent. The exterior angle d equals the angles a plus b. When two straight lines cross, vertically opposite angles are equal. Co-Exterior Angles: Exterior angles on the same side of the transversal. Scroll down the page for more examples and solutions. Exterior Angles of a Triangle Worksheet 1 - This angle worksheet features 12 different triangles, all with one clearly identified exterior angle, represented by x.. Linear Pair of Angles If you count one exterior angle at each vertex, the sum of the measures of the exterior angles of a polygon is always 360°. Simply add the two non-adjacent angles, and you have found the measure of the exterior angle. The exterior angle d is greater than angle a, or angle b. Theory For straight line refer to Activity […] ... As Shown below, there are also two pairs of alternate interior angles and two pairs of alternate exterior angles. Materials Required Cardboard sheet Adhesive Glazed papers White chart paper Geometry box Tracing paper Cutter Prerequisite Knowledge Straight angle Exterior angle property of a triangle. The side opposite to the largest angle of a triangle is the largest side. Hence the lines p and q are parallel. When exterior alternate angles are equal, the lines are parallel. An exterior angle is the angle formed on the outside of the triangle. If ∠H = 60°, ∠E = 120° since those … Properties of Angles. How to use the Consecutive Interior Angles Theorem? - Corresponding angles - Alternate angles - Co-interior angles (supplementary) Angle sum of triangles . Properties of Angles and Straight Lines 1. Any exterior angle of the triangle is equal to the sum of its interior opposite angles. Grades K-8 Worksheets. Types of triangles. In this article, we will learn about such transversals and how they help us in finding different properties … We can use our knowledge of parallel lines to prove (deductively) this theorem. So in the below figure ( ∠4, ∠5) , ( ∠3, ∠6) are Co-interior angles or consecutive angles or allied interior angles. Well, transversal is one of the main connecting links between any two lines (or parallel lines). The following figures give the some examples of co-interior angles. We can see that ∠B and ∠H are exterior alternate angles. The exterior angle of a triangle is equal to the sum of its interior opposite angles. Exterior angles lie outside the parallel lines. 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