Question

Determine the measure of angle ECB.

Question 1 options:

1)

88.25°

2)

183.5°

3)

176.5°

4)

91.75°

Answer 1

You are correct 91.75 is the answer

Explanation:

This is a cyclic quadralterial since all the. vertices of the quadralterials touch the circle circumference. Opposite angles are supplementary in cyclic quadralterials. Angle C and Angle D are opposite angles so

`7x + 20 + 9x - 4 = 180`

`16x + 16 = 180`

`16x = 164`

`x = 10 (4)/(16)`

`x = 10.25`

Plug 10.25 into 7x+20

`7(10.25) + 20 = 91.75`

You are correct

Answer 2

4) 91.75

Explanation:

7x+20+9x-4=180

16x=164

x=10.25

7(10.25)+20=

71.75+20=91.75