Question

Help please, would it be C?

Find the measures of the indicated angles in circle O. Which statement is NOT true? (The figure is not drawn to scale.)


A. a = 53

B. b = 106

C. c = 73

D. d = 37

Answer 1

By inspection, we can see that either B or C must be incorrect, since they don't add up to 180.

what would be your next step?

Answer 2

im not sure , someone earlier was saying to look at the diameter of the line in the circle.

Answer 3

would you look at angle D?

Answer 4

haha, to be honest, I'm not sure how to do this, woah :/ Okay, let's figure this out together. We know (a) and (d) is correct. So there's a right angle on top.

Answer 5

are *

Answer 6

okay , well it mentions something about indirect angle to O so could it be A? lol im so confused

Answer 7

C is incorrect. I'll show you why now

Answer 8

An "inscribed angle" (examples are d and a) equals 1/2 the "intercepted arc"

A central angle (examples: c and b) equals its intercepted arc

Answer 9

woah, i've never done this branch of mathematics :/

Answer 10

though hard to see (and amazing) the 53 deg inscribed angle equals angle a (they both intercept the same arc)

Answer 11

it's trig :/ absolutely the worst !

Answer 12

inscribed angle d+53 make 90 because together they intercept 1/2 the circle (180 degrees) and so they are 1/2 of 180

Answer 13

so you can find d

Answer 14

angle c and angle d intercept the same arc. but c is a central angle, it is twice as big as d

Answer 15

Is that enough to figure out the answer?

Answer 16

no sorry , im still very confused. It still seems as if maybe angle b is correct

Answer 17

start with d. d+53=90 what is d?

Answer 18

37?

Answer 19

yes 37+53= 90

so choice D is correct.

also, angle a and 53 are equal (both intercept the same arc)
a=53
A is correct

Answer 20

angle c is twice angle d

d is 37
c is 2*37= 74

Answer 21

ohh , okay i see . so it can be either ?

Answer 22

and to finish, b (central angle) is twice 53 (an inscribed angle) so b= 2*53=106

Answer 23

so A, B and D are correct and choice C is close but wrong.

Which statement is NOT true?
choice C

Answer 24

ohh , okay i see . so it can be either ?

I don't understand the question.

Answer 25

yayy , so i was correct ! thank you!

Answer 26

It is better to understand the idea.

Answer 27

very true. im still working on trying to learn my formulas and angles , its a bit tricky