Unit 8 Study Guide

Use the formula, S=(n-2)x180

• 4860

• 5220

• 166.7

• 4500

Use the formula, S=(n-2)x180, but now you need to solve for n. The problem gives you the s.

• 11 sides

• 15 sides

• 13 sides

• 16 sides

We have five sides, so it is a Pentagon. We can set all of our expressions equal to our sum of the interior angles of a Pentagon. Then plug your x back into angle s.

• 151

• 121

• 134

• 155

This is a regular hexagon, which means all the angles in this hexagon will equal 11x+21. Set 6(11x+21)=the sum of a hexagon and solve for x.

Mathematical Equivalence

ON

This is a regular nonagon, we are looking for the exterior angle for this nonagon. we know that all outside angles add up to 360, so we could divide 360 by the number of sides to find x.

Mathematical Equivalence

ON

Mathematical Equivalence

ON

We know that in order to find the number of sides, we would have to divide 360 by the measure of our exterior angle, but in this instance, it gives us our interior angle. We know that the exterior and interior are supplementary. First find the exterior angle then do 360 divided by that.

• 12

• 30

• 15

• 25

Which of the following is always true for a parallelogram?

• A

• B

• C

• D

Remember inside a parallelogram, opposite angles are congruent. Find angle D

• 127

• 143

• 155

• 162

We know that these two angles will be congruent because they are the base angles of the isosceles triangle in our rectangle, so set these equal to each other. In order to find the angle that we are missing, plug the x back into either expression, then subtract that answer from 90.

• 22

• 25

• 28

• 24