Geometry: Chalter 11 Flashcards
Postulate 18
Area congruence postulate
If two figures are congruent then they have the same area
Postulate 17
The area of a square is the square of the length of a side.
A=s^2
Postulate 19
Area addition postulate
The area of the region is the sum of the areas of it’s nonoverlapping parts
Theorem 11-1
The area of a rectangle equals the product of its base and height
A=bh
Theorem 11-2
The area of a parallelogram equals the product of a base and the hate to that base
A=bh
Theorem 11-3
The area of a triangle equals half the product of a base and the height to that base
A=bh
Theorem 11-4
The area of a rhombus equals half the product of it’s diagonals
A=1/2d(1)d(2)
Theorem 11-5
The area of a trapezoid equals half the product of the height and the sum of the bases
A=1/2h(b{1}+b{2})
Center of a regular polygon
The center of the circumscribed circle
Radius of a regular polygon
Distance from the center to a vertex
Central angle of the regular polygon
Angle formed by two radii drawn to consecutive vertices
Apothem of a regular polygon
Perpendicular distance from the center of the polygon to a side
Theorem 11-6
The area of a regular polygon is equal to half the product of the apothem and the perimeter
A=1/2ap
Formula for the length of a sector
X/360*2pi.r
Formula for area of a sector
X/360*pi.r^2
