SAT Prep Class
Unit 2: Geometry Review
Day 11: Triangles
Objectives: Identify types of triangles and find the missing parts of a triangle. Find the area
and perimeter of a triangle.
Warm Up
3000
The projected sales volume of a video game cartridge is given by the function s(p) = 2𝑝+𝑎 where
s is the number of cartridges sold in thousands, p is the price per cartridge in dollars, and a is a
constant. If according to projections, 100,000 cartridges are sold at $10 per cartridge, how many
cartridges will be sold at $20 a cartridge?
A) 20,000
B) 50,000
C) 60,000
D) 150,000
E) 200,000
SAT Prep Class
Unit 2: Geometry Review
Day 11: Triangles
Objectives: Identify types of triangles and find the missing parts of a triangle. Find the area
and perimeter of a triangle.
Vocabulary and Formulas:
Area of a triangle =
The sum of the interior angles of a triangle is
Similar Triangles have the same shape: The ratios of the sides are proportional:
Isosceles triangles has at least
sides
Equilateral triangles have all
sides congruent
A right triangle has a
angle and two acute angles.
SOHCAHTOA:
sin  
length of side opposite 
O
 sin  
length of hypotenuse
H
cos  
length of side adjacent 
A
 cos 
length of hypotenuse
H
tan  
length of side opposite 
O
 tan  
length of side adjacent 
A

𝐴𝐵
𝐷𝐸
𝐵𝐶
𝐶𝐴
= 𝐸𝐹 = 𝐹𝐷
Special Right Triangle Relationships:
Example 1: If a triangle has sides of length 15 and 10, what are the possibilities for the third
side?
Example 2: List the angles in order from smallest to largest if a triangle has sides a = 15, b = 20,
and c = 8
Example 3: Solve for x if the angles in a triangle have measures 60º, 2xº, and xº
Example 4: Find the missing side in the similar triangles below:
Example 5: Find the value of x in the right triangles below:
Class work: 129 – 130
Homework; p 135 – 139
Example 6: What is the value of x in the picture below: