All SAT Math Resources
Example Questions
Example Question #135 : Sat Mathematics
Solve each problem and decide which is the best of the choices given.
Solve for .
To solve for , you must first solve for .
All triangles' angles add up to .
So subtract from to get , the value of .
Angles and are supplementary, meaning they add up to .
Subtract from to get .
, so .
Example Question #136 : Sat Mathematics
Refer to the above figure. Evaluate .
is marked with three congruent sides, making it an equilateral triangle, so . This is an exterior angle of , making its measure the sum of those of its remote interior angles; that is,
has congruent sides and , so, by the Isosceles Triangle Theorem, . Substituting for and for :
and form a linear pair and are therefore supplementary - that is, their degree measures total . Setting up the equation
and substituting:
Example Question #132 : Plane Geometry
Figure is not drawn to scale.
Refer to the provided figure. Evaluate .
is an equilateral, so all of its angles - in particular, - measure . This angle is an exterior angle to , and its measure is equal to the sum of those of its two remote interior angles, and , so
Setting and , solve for :
Example Question #1 : Acute / Obtuse Triangles
If a = 7 and b = 4, which of the following could be the perimeter of the triangle?
I. 11
II. 15
III. 25
I Only
I and II Only
II Only
II and III Only
I, II and III
II Only
Consider the perimeter of a triangle:
P = a + b + c
Since we know a and b, we can find c.
In I:
11 = 7 + 4 + c
11 = 11 + c
c = 0
Note that if c = 0, the shape is no longer a trial. Thus, we can eliminate I.
In II:
15 = 7 + 4 + c
15 = 11 + c
c = 4.
This is plausible given that the other sides are 7 and 4.
In III:
25 = 7 + 4 + c
25 = 11 + c
c = 14.
It is not possible for one side of a triangle to be greater than the sum of both of the other sides, so eliminate III.
Thus we are left with only II.
Example Question #141 : Sat Mathematics
Which of the following measurements can NOT represent the sides of a triangle.
Given the Triangle Inequality, the sum of any two sides of a triangle must be greater than the third side.
Given the measurements :
Therefore, these lengths cannot represent a triangle.
Example Question #142 : Sat Mathematics
If triangle ABC has vertices (0, 0), (6, 0), and (2, 3) in the xy-plane, what is the area of ABC?
10
20
12
9
18
Example Question #141 : Geometry
The height, , of triangle in the figure is one-fourth the length of . In terms of h, what is the area of triangle ?
If *, then the length of must be .
Using the formula for the area of a triangle (), with , the area of the triangle must be .
Example Question #1 : How To Find The Height Of An Acute / Obtuse Triangle
Find the height of a triangle if the area of the triangle = 18 and the base = 4.
1
6
9
4
9
The area of a triangle = (1/2)bh where b is base and h is height. 18 = (1/2)4h which gives us 36 = 4h so h =9.
Example Question #141 : Sat Mathematics
and are similar triangles. The perimeter of Triangle A is 45” and the length of two of its sides are 15” and 10”. If the perimeter of Triangle B is 135” and what are lengths of two of its sides?
The perimeter is equal to the sum of the three sides. In similar triangles, each side is in proportion to its correlating side. The perimeters are also in equal proportion.
Perimeter A = 45” and perimeter B = 135”
The proportion of Perimeter A to Perimeter B is .
This applies to the sides of the triangle. Therefore to get the any side of Triangle B, just multiply the correlating side by 3.
15” x 3 = 45”
10” x 3 = 30“
Example Question #1 : How To Find The Length Of The Side Of An Acute / Obtuse Triangle
A triangle has sides of length 8, 13, and L. Which of the following cannot equal L?
4
15
6
7
9
4
The sum of the lengths of two sides of a triangle cannot be less than the length of the third side. 8 + 4 = 12, which is less than 13.