All ISEE Upper Level Quantitative Resources
Example Questions
Example Question #66 : Circles
Figure NOT drawn to scale.
Refer to the above diagram. is the arithmetic mean of and .
Which is the greater quantity?
(a)
(b)
(a) and (b) are equal
(b) is the greater quantity
(a) is the greater quantity
It is impossible to determine which is greater from the information given
(a) and (b) are equal
is the arithmetic mean of and , so
By arc addition, this becomes
Also, , or, equivalently,
, so
Solving for :
Also,
If two tangents are drawn to a circle, the measure of the angle they form is half the difference of the measures of the arcs they intercept, so
Example Question #12 : How To Find The Angle Of A Sector
Figure NOT drawn to scale
In the above diagram, .
Which is the greater quantity?
(a)
(b)
It is impossible to determine which is greater from the information given
(a) is the greater quantity
(a) and (b) are equal
(b) is the greater quantity
(a) and (b) are equal
is a right triangle whose hypotenuse has length times that of leg . This is characteristic of a triangle whose acute angles both have measure -and consequently, whose acute angles are congruent. Therefore,
These inscribed angles being congruent, the arcs they intercept, and , are also congruent.
Example Question #13 : How To Find The Angle Of A Sector
Figure NOT drawn to scale
In the above diagram, .
Which is the greater quantity?
(a)
(b)
(b) is the greater quantity
It is impossible to determine which is greater from the information given
(a) and (b) are equal
(a) is the greater quantity
(a) is the greater quantity
is an inscribed angle, so its degree measure is half that of the arc it intercepts, :
.
and are acute angles of right triangle . They are therefore complimentary - that is, their degree measures total . Consequently,
.
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