Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Circle

Expert replies

by aslan » Wed Nov 24, 2010 10:19 am
@rishab1988: because angle ADC got bisected in two equal angles by 'bisector' DE, making equal angles of ADE and EDC.
Join the discussion

by martie_11 » Wed Nov 24, 2010 12:03 pm
Hi there...unfortunately, I still don't understand how ADE = DCE...can you please explain?

Thank you.
Join the discussion

by aslan » Wed Nov 24, 2010 12:13 pm
@martie_11: For this you may like to visit the 'youtube' link provided in the first few messages, detailing the theorem.

That theorem was what I was looking for!.Thanks everyone.Any more questions like this will be really appreciated.
Join the discussion

by diebeatsthegmat » Wed Nov 24, 2010 5:05 pm
goyalsau wrote:angle ADE = Angle DCE

Because of Alternate Segment Theorem , - if you have any doubts look at the link https://www.youtube.com/watch?v=nwOSsjLDACQ

Lets Assume Angle AED = e

and angle ADE = x,
which means ADE = DCE = EDC = x

in Triangle DEC

x + x + 180 - e = 180

e = 2x


in Triangle AED

24 + e + x = 180

24 + 3x = 180

x = 52

Angle ACB is equal to 90

90 = 52 + theta

theta = 38
man!
Join the discussion

by goyalsau » Wed Nov 24, 2010 8:07 pm
Rahul@gurome wrote:
BC is neither a tangent to the large circle nor to the smaller.
BC would've been the tangent at point C only if joining the radius of the circle and C resulted in a 90° the line and BC. But as AC is perpendicular BC at point C and AC is not a part of radius of any of the circles, BC is not tangent to any of them.
I just Want to rephrase what you said, to clear my understanding of Tangent,

line passing through the circumference of the circle will be a tangent to the circle if the angle formed by joining the radius of the circle and the line is 90 Degree at that particular point.

IF The line if passing through the circumference but is not making a 90 degree angle with line that will be made by joining that particular point and the center of the circle then , WE can not call that line a tangent.

Guys please Correct me if am wrong ... And if am right then also please do let me know..........
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Join the discussion

by beat_gmat_09 » Wed Nov 24, 2010 8:51 pm
goyalsau wrote:
Rahul@gurome wrote:
BC is neither a tangent to the large circle nor to the smaller.
BC would've been the tangent at point C only if joining the radius of the circle and C resulted in a 90° the line and BC. But as AC is perpendicular BC at point C and AC is not a part of radius of any of the circles, BC is not tangent to any of them.
I just Want to rephrase what you said, to clear my understanding of Tangent,

line passing through the circumference of the circle will be a tangent to the circle if the angle formed by joining the radius of the circle and the line is 90 Degree at that particular point.

IF The line if passing through the circumference but is not making a 90 degree angle with line that will be made by joining that particular point and the center of the circle then , WE can not call that line a tangent.

Guys please Correct me if am wrong ... And if am right then also please do let me know..........
Absolutely correct.
Hope is the dream of a man awake
Join the discussion