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Question #14
Find m ZECF
75°
28r-4
30x-1
1.5.x
3

Question #14 Find m ZECF 75° 28r-4 30x-1 1.5.x 3-example-1
User Prolific
by
8.3k points

1 Answer

3 votes

Answer:

∠ ECF = 75°

Explanation:

the central angle of a circle is equal to the arc that subtends it, then

DE = 30x - 1

the sum of the arcs in a circle = 360° , that is

FD + DE + EF = 360° , so

28x - 4 + 30x - 1 + 15x = 360

73x - 5 = 360 ( add 5 to both sides )

73x = 365 ( divide both sides by 73 )

x = 5

then

EF = 15x = 15(5) = 75°

and so ∠ ECF = 75°

User Stardt
by
7.7k points