Answer:
144°
Step-by-step explanation:
step 1
Find the measure of the central angle of the regular pentagon
Divide 360 degrees by 5 (the number of sides)

Let
c----> the center of the pentagon
we know that
m∠ECA=72°
m∠ACB=72°
therefore
m∠ECB=m∠ECA+m∠ACB
substitute the values
m∠ECB=72°+72°=144°
The measure of angle ECB is equal to the degrees that the pentagon rotate
Answer:
300 min or 5 hours
Step-by-step explanation:
so if it pumps 0.5 gallons per minute than in 2 minutes it would pump 1 whole gallon so with that we know 1gallon=2 minutes.
so with that we multipy both sides by 150 which will be 150 galons=300 minutes or 5 hours
5(a + 3b) = 5(9 + 3(2)) = 5(9 + 6) = 5(15) = 75
Answer:
#1
Step-by-step explanation:
Answer:
Dimensions of original room = 12 x 12 feet.
Explanation:
Let the size of old square room be a x a.
New dimension = ( a+4 ) x ( a + 6 )
We have area of the new room will be 144 square feet greater than the area of the original room.
So, ( a+4 ) x ( a + 6 ) = a x a + 144
a²+10a+24= a²+144
10a = 120
a = 12 feet.
Dimensions of original room = 12 x 12 feet.