Answer:
17/28
if you're solving for cosine
Step-by-step explanation:
It's an isosceles triangle so angles A and BCA are congruent.
Angle BCA is the supplement of BCD, so 180-109 = 71.
Angle A is congruent to that, so A=71 degrees.
Let's see if we can get that in the format they want, kind of as a proof.
1. ∠BCD=109° Reason: Given
2. AB ≅ BC Reason: Given
3. ∠BCA = 71° Reason: Linear pairs are supplementary
4. ΔABC is isosceles. Reason: Definition of isosceles
5. ∠A ≅ ∠BCA Reason: Isoceles triangle theorem
6. ∠A = 71° Reason: Def congruent
Answer: 71 degrees
Problem 11
Answer: Angle C and angle F
Explanation: Angle C and the 80 degree angle are vertical angles. Vertical angles are always congruent. Angle F is equal to angle C because they are alternate interior angles.
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Problem 12
Answer: 100 degrees
Explanation: Solve the equation E+F = 180, where F = 80 found earlier above. You should get E = 100.
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Problem 13
Answer: 80 degrees
Explanation: This was mentioned earlier in problem 11.
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Problem 14
Answers: complement = 50, supplement = 140
Explanation: Complementary angles always add to 90. Supplementary angles always add to 180. An example of supplementary angles are angles E and F forming a straight line angle.
Answer:
Average speed is 48 km per hour
Step-by-step explanation:
A student drove to the university from her home and noted that the odometer reading of her car increased by 16.0 km. The trip took 20.0 min. (a) What was her average speed? in km/hr
Distance traveled is 16 km and the time taken is 20 minutes
convert minutes into hour. to convert minutes into hour we divide by 60 because 1 hour = 60 minutes

so time = 1/3 and distance = 16
Average speed = distance by time

Average speed is 48 km per hour