In the figure above, AC = BC. If m

80 degrees

Step-by-step explanation:

since ac and bc equal each other, it is an isosceles triangle. due to that, the measure of angle a and b are 50. so the measure of angle c is 80. due to some theorem, angle ecd is equal to angle acb. so ecd = 80

b

step-by-step explanation:

the equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (3, - 5) ← 2 points on the line

m = = = - 3

with m = - 3 and (a, b) = (3, - 5), then

y - (- 5) = - 3(x - 3), that is

y + 5 = - 3(x - 3) → b

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64