Vertical Angles: Find the Supplementary Angles (photo provided)

105°

Step-by-step explanation:

The given angles are vertical and congruent , then

8x - 21 = 6x + 3 ( subtract 6x from both sides )

2x - 21 = 3 ( add 21 to both sides )

2x = 24 ( divide both sides by 2 )

x = 12

Then

6x + 3 = 6(12) + 3 = 72 + 3 = 75°

Supplementary angles sum to 180° , thus

supplementary angle = 180° - 75° = 105°

answer: 180

step-by-step explanation:

12-2=10

20-2=18

10x18=180

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.