Urgent geometry AD is a diameter of E and BE is perpendicular to AD. If m CD = 30°, what is mBEC?

30°
150°
90°
60°

Which of the following combinations cannot be the side lengths of a triangle?

2.3 inches, 3.4 inches, and 3.2 inches
4.8 inches, 5 inches, and 1.2 inches
2.5 inches, 2.5 inches, and 2.5 inches
6.7 inches, 1.1 inches, and 7.9 inches

AD and BE is perpendicular => angle BED = 90 deg.

Otherwise angle CED = arc CD = 30 deg

=> angle BEC = angle BED - angle CED = 90 - 30 = 60 deg

Suppose a, b and c are 3 sides of a triangle in which a < b < c.

As property of length of sides a, b, and c of a triangle:

c - b < a < c + b

b - a < c < b + a

c - a < b < c + a

=> 6.7 inches, 1.1 inches, and 7.9 inches are not sides of a triangle

Check:

7.9 - 1.1 < 6.7 <=> 6.8 < 6.7  <=> invalid!

Hope this helps!

:)

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional