since line AB and CD make all right angles (given) angles 6+7+8 will equal 90 degrees.
According to the verticle angles rule:
angle 2 is equal to angle 6
angle 3 is equal to angle 7
angle 4 is equal to angle 8.
which proves that angle 2+4+7=90 degrees
Using the properties of arcs and inscribed angles, B is 110/2=55.
We know that 
and 
Substitute in the value. 
Use a calculator to multiply. 
Nooooooooooooooooooooooooooooooooooooo
(8 x 320)^1/3
(2560)^1/3
(64*40)^1/3
64^1/3 *40^1/3
4 * (8^1/3) * 5^1/3
4 * 2 * 5^1/3
8 *5^1/3
None of your choices are written correctly
