Answer:
SAS postulate
Step-by-step explanation:
AD (common)
AC = BD (both are diameters)
Angle COD = Ange AOD (vertically opposite angles)
Angle CAD = Angle BAD (angle on the circumference is half the angle at the centre)
Therefore, ABD and DCA are congruent by SAS postulate
Answer:
7 hours 30min
Step-by-step explanation:
Step one :
Given data
We are told that Erica can paint 1 room in 5hours
Her work rate is 1/5 room per hour
And also with the assistance of her friend they can paint 1 room in 3 hours
Hence their combined work rate is 1/3 room per hour
Step two
The combined work expression is
1/A+1/B=1/T
Where A=Erica's work rate
B=Rachael's work rate
T=combined work
1/5+1/B=1/3
1/B=1/3-1/5
1/B=5-3/15
1/B=2/15
B=15/2
B=7.5 hours
It will take Rachel 7 hours 30min to paint the room
Α = 1- (95/100) = 1-0.95 = 0.05
p = 1- α/2 = 1- 0.05/2 = 1-0.025 = 0.975
Degrees of freedom, df = Sample size -1 = 11-1 = 10
From t-tables, with cumulative probability pf 0.975 and df of 10,
Critical value = 2.228
