Question

find the angle measures of the quadrilateral (pic show)

Answer 1

Theorem: If a quadrilateral is inscribed in a circle, then opposite angles of the quadrilateral are supplementary.

<B and <D are opposite angles.

<B and <D are supplementary

So,

z/2 + (z/4) + 30 = 180

Solve for z @ineedhelpinmath08

Answer 2

thats what im starting off with .. im just confused on whether i should subtract 30 from 180 or ?

Answer 3

Yes, do that >> subtract 30 from 180

Post what you get:

z/2 + (z/4) = ?

Answer 4

=150

Answer 5

Carry the equation along:

z/2 + (z/4) = 150

Now, multiply each term (all 3 of them) by 4 to clear the fractions.
Post what you get.

Answer 6

oooh okay

Answer 7

2z=600?

Answer 8

or 3z=600?

Answer 9

4 * z/2 +4* (z/4) =4* 150

2z + z = 600

so which is it, 2z = 600 or 3z = 600?

Answer 10

3z=600 sometimes when i do it in my head i miss something

Answer 11

z=200 then you plug themback into the equations to get the angles

Answer 12

but angle c cant be 200?

Answer 13

Suggestion: Don't do math in your head. Writing it is better. (my opinion)

Answer 14

it is i agree with you

Answer 15

>but angle c cant be 200?

That is true. z = 200.

Angle C is opposite Angle E. They are supplementary.

So, get the measure of Angle E and subtract it from 180 to get the measure of angle C.

Answer 16

angle E is 141. 141-180 = 39

Answer 17

thank you so much for all your help!

Answer 18

well it should be 180-141=39 my bad

Answer 19

141-180 = -39

180 - 141 = 39

Subtraction is not commutative. Order matters.