Half of 36 is 18 so if 18+18=36
2
18
Answer:
All three internal angles are congruent to each other and are each 60°.
Step-by-step explanation:
In an equilateral triangle, the altitudes, the angle bisectors, the perpendicular bisectors, and the medians to each side coincide.
First let's find the angles a and b.
We have then:
sin a = 4/5
a = Asin (4/5)
a = 53.13 degrees.
cos b = 5/13
b = Acos5 / 13
b = 67.38 degrees.
We now calculate cos (a + b). To do this, we replace the previously found values:
cos ((53.13) + (67.38)) = - 0.507688738
Answer:
-0.507688738
Note: there is another way to solve the problem using trigonometric identities.
Speed=distance/time
s=19km/19min=1km/min
