i reaalllyyyyy need the help :) please
you can use the fact that the arc AXB = 196 degrees to find the value of this angle
is there a formula i can plug this into?
I never did arcs when in college (many years ago) so i'm not sure!. Sorry you'll have to google that - or someone else probably knows
there's probably a theorem
the angle marked is 360 - 196 = 164 degrees
this is the angle at the center of the circle
then do you subtract it from 180 and with that answer divide by 2?
that angle is 82 because its 1/2 of 164
now opposite angles of a cyclic quadrilateral add up to 180 so the opposite angle = 180 - 82 = 98
The Theorem: An Angle formed by a chord and a tangent that intersect on a circle is half the measure of the intercepted arc. 1/2 of196=98
- which makes m
thank you !
could you help me with another one?
there you go Mertsj has a quick way
If the measure of angle DEF is 65, what is the measure of arc DE ? http://media.apexlearning.com/Images/200701/18/df4742e6-e568-423e-bfe0-61f1985506e7.gif
Did you read the theorem I posted above?
so do i just double 65
use the theorem Mertsj quoted
easy using that theorem
yep. That's what theorems are for. You prove something once and for all and then you don't have to reinvent the wheel for every similar problem.
true - Its weird but we never touched arc measurements in Geometry in the UK - as I said I'm talking decades ago. Maybe they do now.
yes - i don't understand why they didn't
how about another one?
lol - this is a learning experience for me - OK
In the diagram below, line AB and BC and are tangent to center O. What is the measure of arc ADC?
well as a full circle is 360 degrees arc ADC = 360 - 140
so its 220
thank you so much seriously!
i learned something new myself