Geometry  Problem 21
Plotto's Decagon

Plotto's problem is that he has forgotten his password to operate his spaceship.  As a mnemonic device (memory aid) he made the password to be the sum of the interior angles of a regular decagon.

Plotto has also forgotten that number so now he has calculate how many degrees are in the sum of the interior angles of that decagon.

Put poor Plotto back to his pad on Pluto.  Find how many degrees are in Plotto’s decagon.


Math Scoring Guide
Download the Oregon Math Scoring Rubric 

Name: ________________________ Period: ____
Teacher: ______________________

Date: ___/____/___

CU - Conceptual Understanding 1 2 3 4 5 6

Comments:

PS - Processes & Strategies 1 2 3 4 5 6

Comments:

V - Verification 1 2 3 4 5 6

Comments:

C - Communication 1 2 3 4 5 6

Comments:

ACC - Accuracy 1     4 5  

Comments:

___ May be revised and returned for an improved score.