All SAT II Math I Resources
Example Questions
Example Question #51 : Geometry
Regular Hexagon has perimeter 120. has as its midpoint; segment is drawn. To the nearest tenth, give the length of .
The perimeter of the regular hexagon is 80, so each side measures one sixth of this, or 20. Also, since is the midpoint of , .
Also, each interior angle of a regular hexagon measures .
Below is the hexagon in question, with indicated and constructed; all relevant measures are marked.
A triangle is formed with , , and included angle measure . The length of the remaining side can be calculated using the Law of Cosines:
where and are the lengths of two sides, is the measure of their included angle, and is the length of the third side.
Setting , and , substitute and evaluate :
;
Taking the square root of both sides:
,
the correct choice.
Example Question #21 : Finding Sides
Regular Pentagon has perimeter 80. has as its midpoint; segment is drawn. To the nearest tenth, give the length of .
The perimeter of the regular pentagon is 80, so each side measures one fifth of this, or 16. Also, since is the midpoint of , .
Also, each interior angle of a regular pentagon measures .
Below is the pentagon in question, with indicated and constructed; all relevant measures are marked.
A triangle is formed with , , and included angle measure . The length of the remaining side can be calculated using the law of cosines:
where and are the lengths of two sides, is the measure of their included angle, and is the length of the third side.
Setting , and , substitute and evaluate :
;
Taking the square root of both sides:
,
the correct choice.
Example Question #22 : Finding Sides
If the two legs of a right triangle are and , find the third side.
Step 1: Recall the formula used to find the missing side(s) of a right triangle...
Step 2: Identify the legs and the hypotenuse in the formula...
are the legs, and is the hypotenuse.
Step 3: Plug in the values of a and b given in the question...
Step 3: A special rule about all triangles...
For any triangle, the measurements of any of the sides CANNOT BE zero.
So, the missing side is , or
Example Question #493 : Sat Subject Test In Math I
Regular Pentagon has perimeter 80. and have and as midpoints, respectively; segment is drawn. Give the length of to the nearest tenth.
The perimeter of the regular pentagon is 80, so each side measures one fifth of this, or 16. Since is the midpoint of , .
Similarly, .
Also, each interior angle of a regular pentagon measures .
Below is the pentagon with the midpoints and , and with constructed. Note that perpendiculars have been drawn to from and , with feet at points and , respectively.
is a rectangle, so .
, or
. Substituting:
For the same reason,
.
Adding the segment lengths:
,
Rond answer to the nearest tenth.
Example Question #61 : Geometry
Regular Pentagon has a perimeter of eighty.
Give the length of diagonal to the nearest tenth.
The perimeter of the regular pentagon is 80, so each side measures one fifth of this, or 16. Also, each interior angle of a regular pentagon measures .
The pentagon, along with diagonal , is shown below:
A triangle is formed with , and included angle measure . The length of the remaining side can be calculated using the law of cosines:
,
where and are the lengths of two sides, the measure of their included angle, and the length of the side opposite that angle.
Setting , and , substitute and evaluate :
Taking the square root of both sides:
,
the correct choice.
Example Question #11 : How To Find The Length Of The Diagonal Of A Rhombus
is rhombus with side lengths in meters. and . What is the length, in meters, of ?
12
15
5
30
24
24
A rhombus is a quadrilateral with four sides of equal length. Rhombuses have diagonals that bisect each other at right angles.
Thus, we can consider the right triangle to find the length of diagonal . From the given information, each of the sides of the rhombus measures meters and .
Because the diagonals bisect each other, we know:
Using the Pythagorean theorem,