Chapter 7 – Polygons

Flashcards covering key polygon angle concepts from the notes, including interior angle sums, the (n-2)×180 formula, and exterior angles of triangles.

What is the sum of interior angles of all quadrilaterals?

360 degrees

How can we prove that the sum of interior angles of a quadrilateral is 360 degrees?

Draw one diagonal to split the quadrilateral into two triangles; each triangle has interior angles summing to 180 degrees, so total is 2×180 = 360 degrees.

What is the formula for the total interior angle of an n-sided polygon?

(n − 2) × 180 degrees

How many triangles can be formed by drawing diagonals from one vertex in an n-sided polygon?

n − 2

What is the total interior angle of a pentagon (5-sided polygon)?

(5 − 2) × 180 = 540 degrees

What is the sum of exterior angles, one at each vertex, of a triangle?

360 degrees

Where can you learn more about exterior angles of triangles as suggested in the notes?

From the GeoGebra links provided: https://www.geogebra.org/m/KWb7RrTu and https://www.geogebra.org/m/pPhgGMse