Question

pls help me to solve this problem this is to difficult​

Answer 1

Answer:

d (none)

Step-by-step explanation:

Let the 3 out of 4 angles of quadrilateral be x , 5x and 6x

mean of these angles is given to be 60

therefore,

$\frac{x + 5x + 6x}{3} = 60 \\ \frac{12x}{3} = 60 \\ 4x = 60 \\ x = 15$

therefore the angles are

$x = 15 \: degree \\ 5x = 75 \: degree \\ 6x = 80 \: degree$

let the fourth angle of quadrilateral to be y.

by angle sum property of quadrilateral, sum of all 4 angles will be 360

therefore,

$x + 5x + 6x + y= 360 \\ 15 + 75 + 80 + y = 360 \\ 90 + 80 + y = 360 \\ 170 + y = 360 \\ y = 360 - 170 \\ y = 190$

therefore, the angles are

15, 75, 80 and 190