psat formulas

Question 1

area of a circle

Answer 1

πr²

Question 2

area of an equilateral triangle

Answer 2

(s²√3)/4

s=side length

Question 3

area of a parallelogram

Answer 3

b●h

Question 4

Area of a Rectangle

Answer 4

l●w

Question 5

Area of a Rhombus

Answer 5

½(d1xd2)

d1 and d2 are the lengths of the diagonals in the rhombus

Question 6

Area of a Square

Answer 6

s²

Question 7

Area of a Trapezoid

Answer 7

½h(b1 + b2)

b1 and b2 are the two bases of the trapezoid

Question 8

Area of a Triangle

Answer 8

½bh

Question 9

Axis of Symmetry for Standard Quadratic

Answer 9

x=-b/2a

Question 10

Circumference

Answer 10

2𝝅r

Question 11

Compound Interest

Answer 11

A=P(1+r/n)^nt

t= time
n= number of years
r = interest

Question 12

Density

Answer 12

mass/volume

Question 13

Direct Variation

Answer 13

y=kx
Direct variation means that as one quantity increases, the other also increases proportionally, like when baking cookies - the more dough you use (x), the more cookies you get (y).

Question 14

Distance (between 2 points)

Answer 14

d= √(x₂ - x₁) ² + (y₂ - y₁)²

Question 15

Distance (travel)

Answer 15

d=rt

r= rate (speed)

t= time (time is takes to get there)

Question 16

Midpoint

Answer 16

(x1+x2)/2,( y1+y2)/2

Question 17

Quadratic Formula

Answer 17

-b±[√b²-4ac]/2a

Question 18

Point Slope Formula

Answer 18

y-y1=m(x-x1)