ch 11, like all of it

Question 1

Area of a parallelogram

Answer 1

A=bh

Question 2

Area of a triangle

Answer 2

A=1/2(bh)

Question 3

Area of a rhombus

Answer 3

A= [ d1(d2) ] 1/2

OR

A= bh (depends on the info you have)

Question 4

Area of a trapezoid

Answer 4

A = 1/2h (b1 + b2)

Question 5

The radius of a polygon inscribed in a circle goes from the center to the…

Answer 5

…vertex of the polygon

Question 6

The radius of a polygon inscribed inside a circle is from the center of the polygon/circle to the…

Answer 6

…vertex of the polygon

Question 7

A central angle is formed by-

Answer 7

-two radii drawn to the consecutive vertices

Question 8

Apothem

Answer 8

the perpendicular distance from the center of the polygon to a side

Question 9

Formula to find the area of a regular polygon

Answer 9

A= 1/2 a (apothem) times p (perimeter)

Question 10

The area of a regular polygon is equal to half-

Answer 10

-the product of the apothem and the perimeter

Question 11

Circumference

Answer 11

C=2π r

Question 12

Area of a circle

Answer 12

A=π r^2

Question 13

EX:
A ferris wheel has a diameter of 42 ft. How far will a rider travel during a 4-min ride if the wheel rotates once every 20 seconds?

Answer 13

there are 12 20 seconds in 4 minutes,

c= 2π * 21 = 42π * 12

505π ft

Question 14

Arc length formula

Answer 14

m of arc/360 times 2π r

Question 15

Area of sector

Answer 15

m of arc/360 times π r^2

Question 16

If two triangles have equal heights, then the ratio of their areas equals-

Answer 16

-the ratio of their bases

Question 17

If two triangles have equal bases, then the ratio of their areas equals-

Answer 17

-the ratio of their heights

Question 18

If two triangles are similar, then the ratio of their areas equals-

Answer 18

-the square of their scale factor

Question 19

If the scale factor of two similar figures is a : b, then (2)

Answer 19

1) The ratio of the perimeters is a : b
2) The ratio of the areas is a^2 : b^2

Question 20

Imagine circle R is in circle S*

Suppose a point P of region S is picked at random. The probability that P is in region R equals-

Answer 20

R= Area of R/ Area of S