Geometry Quadrilaterals & Polygons 4

Question 1

What is the sum of interior angles of a decagon?

Accepted Answer

1440°

Answer

With n=10, (10-2)×180° = 8×180° = 1440°.

Question 2

In a square, the diagonal relates to side s by which length?

Accepted Answer

s√2

Answer

The diagonal of a square equals side length times √2.

Question 3

Which quadrilateral is NOT always a parallelogram?

Accepted Answer

Trapezoid

Answer

A trapezoid has only one pair of parallel sides, so it is not a parallelogram.

Question 4

How many sides does a polygon have if the sum of its interior angles is 1080°?

Accepted Answer

8

Answer

Solving (n-2)×180° = 1080° gives n-2 = 6, so n = 8.

Question 5

The opposite angles of a parallelogram are:

Accepted Answer

Congruent

Answer

Opposite angles in a parallelogram are always equal in measure.

Geometry Practice Test