Geometry

Question 1

Triangle - area

Answer 1

a x ha/2
b x hb/2
c x hc/2

Question 2

Sum of interior angles of a triangle

Answer 2

180

Question 3

Isosceles triangle - area

Answer 3

a x ha/2
c x hc/2

Question 4

Isosceles triangle - height

Answer 4

hc = mc = lc

Question 5

Equilateral triangle - area

Answer 5

a x ha/2
a^2√3/4

Question 6

Equilateral triangle - angles

Answer 6

always 60 degrees each

Question 7

Equilateral triangle - height

Answer 7

a√3/2

Question 8

Right triangle - area

Answer 8

axb/2
cxhc/2

Question 9

Pythagorean Triplets

Answer 9

3 4 5
6 8 10
9 12 15
12 16 20
—————-
5 12 13

Question 10

Special rights triangle - 30 - 60 - 90

Answer 10

30 - 60 - 90
a - a√3 - 2a

Question 11

Special rights triangle - 45 - 45 - 90

Answer 11

45 - 45 - 90
a - a - a√2

Question 12

Circle - circumference

Answer 12

2пr

Question 13

Circle - area

Answer 13

пr^2

Question 14

Arc of Circle - length

Answer 14

L/360 x circumference

Question 15

Arc of Circle - sector area

Answer 15

L/360 x area

Question 16

Trapezoid - area

Answer 16

(a + b) x h/2

Question 17

Parallelogram - area

Answer 17

a x ha or b x hb

Question 18

Parallelogram - diagonals

Answer 18

they separate each other into equal halves, but they are not equal, they are not angle bisectors and are not perpendicular

Question 19

Parallelogram - angles

Answer 19

adjacent angles are supplementary
opposite angles have the same measure

Question 20

Rectangle - diagonals

Answer 20

diagonals are equal
four isosceles triangles are formed

Question 21

Rhombus/Diamond - area

Answer 21

a x ha or d1 x d2/2

Question 22

Rhombus/Diamond - diagonals

Answer 22

d1 and d2 are not equal, but they are angle bisectors and are perpendicular

Question 23

Square - area

Answer 23

a^2 or d^2/2

Question 24

Square - diagonals

Answer 24

d = a√2
a diagonal forms a special rights triangle - 45 45 90

Question 25

Rectangular solid - Surface Area

Answer 25

2ah + 2ab + 2bh

Question 26

Rectangular solid - Volume

Answer 26

Bh = abh
B = ab = area of the base

Question 27

Rectangular solid - Diagonal

Answer 27

Longest distance in the figure
D = √a^2 + b^2 + h^2

Question 28

Cylinder - Surface Area

Answer 28

2(пr^2) + ((2пr) x h)

Question 29

Cylinder - Volume

Answer 29

Bh = п x r^2 x h
B = п x r^2

Question 30

Cube - Surface Area

Answer 30

6 x a^2
because we have 6 squares

Question 31

Cube - Volume

Answer 31

a^3

Question 32

Cube - Diagonals

Answer 32

D = a√3
d = a√2

Question 33

Distance between two points

Answer 33

|AB| = √(x1 - x2)^2 + (y1 - y2)^2

Question 34

Coordinates of Midpoint Segment

Answer 34

M = (x1 + x2/2; y1 + y2/2)

Question 35

Slope of Line by Equation

Answer 35

y = kx + b

Question 36

Slope of Line by Two Points

Answer 36

k = y2 - y1/x2 - x1

Question 37

Two lines are parallel when

Answer 37

k1 = k2

Question 38

Two lines are perpendicular when

Answer 38

k1 = - 1/k2

Question 39

the biggest angle of the triangle

Answer 39

is opposite of the biggest side

Question 40

The sum of all exterior angles

Answer 40

is always 360, for any figure

Question 41

The sum of all interior angles for any figure

Answer 41

is always (number of angles - 2) x 180

Question 42

If a triangle is constructed inside a circle and the sides are the chords and the diameter, the angle across will always be

Answer 42

90