Question

If LMNO is a rectangle, and mMON = 30, what is the value of x?

Answer 1

LMNO is a rectangle, and mMON = 30
so
mONL = 30

x = 180 - 2(30)
x = 180 - 60
x = 120

Answer is E. 120

Answer 2

The answer is the option E

`120\°`

Explanation:

we know that

If LMNO is a rectangle

then

The triangle OCN is an isosceles triangle----> (C is the center of the rectangle)

so

`m<MON=m<LNO=30\°` ------> the base's angles of the isosceles triangle

`m<OCN=x\°` -----> by vertical angles

Remember that the sum of the internal angles of a triangle must be equal to
`180\°`

therefore

`2*30\°+x\°=180\°`

solve for x

`x=180\°-2*30\°=120\°`