First we find the measurement of dark dot .
ANd for that we have to use the formula of the angle formed by the intersection of chord .
Let the dark dot be t.
So we have

t and z are linear pair and sum of angles of linear pair =180 degree.
So we get

Answer:
26.8°
Step-by-step explanation:
4x - 20 + 6x - 7 = 90
10x -27 =90
10x = 90+27
10x= 117
x = 11.7
so, the angle R = 4x-20 =4(11.7)-20
= 46.8-20 = 26.8°
Answer: The height of the building is 6.49 meters.
Step-by-step explanation:
This can be translated to:
"A building projects a 7.5 m shadow, while a tree with a height of 1.6 m projects a shadow of 1.85 m.
Which is the height of the building?"
We can conclude that the ratio between the projected shadow is and the actual height is constant for both objects, this means that if H is the height of the building, we need to have:
(height of the building)/(shadow of the building) = (height of the tree)/(shadow of the tree)
H/7.5m = 1.6m/1.85m
H = (1.6m/1.85m)*7.5m = 6.49m
The height of the building is 6.49 meters.
(2x+1)+(3x-5)=5x-4 you just have to try some of them out and see which ones work