The figure shows two sectors in which the arcs AB and CD are arcs of concentric circles, centre 0. BD = AC = 4 cm and angle AOB = 1/2 radians. If the perimeter of ABDC is 16cm, calculate
(a) OB,
(b) the area of ABDC.

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What is the value with a place of tenths in 907.456 1) 0 2) 6 3) 4 4) 5

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?

Y+ 2/y is it a polynomial in one variable or not? and if so, why?