BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Cheat Sheet for Polygons

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 504
Joined: Tue Apr 19, 2011 1:40 pmFollowed by: 11 members
Thanked: 114 times
by knight247 » Tue Aug 30, 2011 4:35 am
Hey,
I'm kinda well versed with the interior and exterior angle formulas for regular polygons i.e.
(1)Sum of interior angles=(n-2)180
(2)Measure of one interior angle=(n-2)180/n

(3)Sum of exterior angles in one direction is 360 and in the other direction is 360
(4)Measure of one exterior angle=360/n

I'm a little confused though about the formulas for irregular polygons
I know that Formula No.1 still applies. Formula 2 does not. I guess I need some clarification on the exterior angles of irregular polygons. Hoping to get some help on that. Detailed explanations would be appreciated. Thanks
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Tue Sep 06, 2011 7:33 am
knight247 wrote:Hey,
I'm kinda well versed with the interior and exterior angle formulas for regular polygons i.e.
(1)Sum of interior angles=(n-2)180
(2)Measure of one interior angle=(n-2)180/n

(3)Sum of exterior angles in one direction is 360 and in the other direction is 360
(4)Measure of one exterior angle=360/n

I'm a little confused though about the formulas for irregular polygons
I know that Formula No.1 still applies. Formula 2 does not. I guess I need some clarification on the exterior angles of irregular polygons. Hoping to get some help on that. Detailed explanations would be appreciated. Thanks
I wouldn't worry about the formulas for exterior angles.

For irregular polygons (where the sides and angles are not all equal) with n sides, the sum of the interior angle is still 180(n-2) degrees.

Since the angles are not equal in an irregular polygon, there is no formula for each interior angle.

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1