Expert I Geometry And Angles (11) 20-2

Question 1

What is an important property about same side interior angles?

This is for parallel lines and a transversal.

Answer 1

Same Side Interior Angles are supplementary (add to 180)

Question 2

What pairs of angles have the same measure when parallel lines are crossed by a transversal line? Name all.

Answer 2

Several pairs of angles have the same measure when parallel lines are crossed by a transversal line:
- corresponding angles
- alternate interior angles
- alternate exterior angles.

Question 3

What are corresponding angles?

Answer 3

Corresponding Angles: same side of transversal and same side of parallel lines (above and right, below and left, etc.)

Question 4

What are alternate interior angles?

Answer 4

Alternate Interior Angles: between the parallel lines and opposite sides of the transversal

Question 5

What are alternate exterior angles?

Answer 5

Alternate Exterior Angles: outside the parallel lines and opposite sides of the transversal

Question 6

What is an important property about angles when two lines cross?

Answer 6

When we have intersecting lines, each pair of Opposite Angles are equal to each other.

Question 7

What is the formula for the sum of the interior angles of a polygon?

Answer 7

S = (n - 2)180°

Where n is the number of sides of the polygon, and S is the sum of the interior angles.

In a regular polygon, you can get the measure of one of these angles by dividing the sum by the number of sides.

We can determine the total sum of angles in convex polygons by counting the number of triangles, less 360 from the centre angle created by all the triangles.
If the polygon is ‘regular’ all the interior angles are the same size. We can divide the angle sum by the number sides to determine how large each angle is.