Answer:
A
Step-by-step explanation:
The exterior angle is equal to the sum of the opposite interior angles.
Call the inside angle D
A+ B + D = 180 sum of the angles of a triangle is 180
C+D = 180 since the form a straight line
Solving for D
D = 180-C
Substitute this into the first equation
A+ B + 180-C = 180
Subtract 180 from each side
A+ B + -C =0
Add C to each side
A + B = C
This proves the theorem
14=17-x
-3=-x
The unknown number is X and u simplify first
Answer:
length of diagonals are BD = 33.039 cm and AC = 38.84 cm
Step-by-step explanation:
given,
sides of parallelogram is 20 cm and 30 cm
Angle between them is 80°. opposite angle of parallelogram are same the opposite angle is same.
other angle = 360° - 80° - 80° + 2 x = 200
x = 100°
Using cosine law
c² = a² + b² - 2ab cos γ
In ΔDAB
BD² = 30² + 20 ² - 2 × 30 × 20 cos 80°
BD = 33.039 cm
now in ΔADC
c² = a² + b² - 2ab cos γ
AC² = 20² + 30² - 2 × 30 × 20 cos 100°
AC = 38.84 cm
length of diagonals are BD = 33.039 cm and AC = 38.84 cm
The answer in decimal format is 15.7
Or 7 radical 5