Math test: 10-1, 10-2, 10-3, 12-7

Composite figures

A figure that is made up of two or more shapes

Apothem

A segment that is drawn from the center of a regular polygon perpendicular to a side of the polygon

Area of a semi circle

A-=1/2πr²

Area of a triangle

A=1/2 (b)(h)

Area of a regular polygon

A=1/2 (perimeter)(apothem) Remember: A=square units

Area of a rhombus

A=1/2(diagonal 1)(diagonal 2)

Area of a trapozoid

A=1/2(h)(base 1+ base 2) h = line segment connecting the 2 bases

Area of a parallelogram

A=b(h)

Area of a circle

A=πr²

Central angle of a regular polygon

An angle formed by two radii drawn to consecutive vertices of the polygon

How to find the circumference of a circle

C = πd (units)

How to find perimeter in a polygon

P=2(b)+2(h)

How to solve the perimeter of a regular polygon

P=ns Step 1: Find the central angle (360/number of sides) Step 2: Split the central angle into 2 by drawing a line down the middle Step 3: Do Tan(the central angle / 2) = x/apothem Step 4: Multiply both sides by the apothem (ex. Xtansidelength) Step 5: Multiply that by 2 so you can get your side Step 6: Multiply that by the number of sides the polygon has

Area addition postulate

The area of a region is the sum of the areas of its non-overlapping parts

Distance formula

Used to find the radius d = √( x₂ - x₁)² + (y₂ - y₁)²

Theorem 12-7-1

center= h, k radius= r (x-h)^2 + (y-k)^2 = r^2