User:

Documento sin título
 Pre-algebra Arithmetics Integers Divisibility Decimals Fractions Exponents Percentages Proportional reasoning Radical expressions Graphs Algebra Monomials Polynomials Factoring Linear Equations Graphs of linear equations Rectangular Coordinate System Midpoint Formula Definition of Slope Positive and negative slope Determine the slope of a line Equations of lines Equation of lines (from graph) Applications of linear equations Inequalities Quadratic equations Graphs of quadratic equations Absolute Value Radical expressions Exponential equations Logarithmic equations System of equations Graphs and functions Plotting points and naming quadrants Interpreting Graphs Relations and Functions Function Notation Writing a Linear Equation from a Table Writing a Linear Equation to describe a Graph Direct Variation Indirect Variation Domain and range Sequences and series Matrices Inverse of a matrix Determinants Inner product Geometry Triangles Polygons 2-D Shapes 3-D Shapes Areas Volume Pythagorean Theorem Angles Building Blocks Geometry Transformations Parallel, coincident and intersepting lines Distances in the plane Lines in space Plane in space Angles in the space Distances in the space Similarity Precalculus Sequences and series Graphs Graphs Definition of slope Positive or negative slope Determine the slope of a line Equation of a line (slope-intercept form) Equation of a line (point slope form) Equation of a line from graph Domain and range Quadratic function Limits (approaches a constant) Limits (approaches infinity) Asymptotes Continuity and discontinuities Parallel, coincident and intersepting lines Introduction to Functions Limits Continuity Asymptotes Trigonometry Trigonometric ratios The reciprocal trigonometric ratios Trigonometric ratios of related angles Trigonometric identities Solving right angles Law of sines Law of cosines Domain of trigonometric functions Statistics Mean Median Mode Quartiles Deciles Percentiles Mean deviation Variance Standard Deviation Coefficient of variation Skewness kurtosis Frequency distribution Graphing statistics & Data Factorial Variations without repetition Variations with repetition Permutations without repetition Permutation with repetition Circular permutation Binomial coefficient Combinations without repetition Combinations with repetition

Areas
Triangle

A triangle is a figure formed when three noncollinear points are connected by segments. Each pair of segments forms an angle of the triangle. The vertex of each angle is a vertex of the triangle.

The sum of the measures of the angles of a triangle is 180.

Area of a triangle
When you know the lenght of the base and the height, you can use the formula:

Area=$\frac{1}{2}$·b·h, where b is the base and h is the height

 Find the area of an acute triangle with a base of 15 inches and a height of 6 inches.

Area=$\frac{1}{2}$·b·h

Area=$\frac{1}{2}$·(15 in)·(6 in)

Area=$\frac{1}{2}$·90 in2

Area=45 in2

Area of a triangle (Heron's Formula)
Heron's formula gives the area in terms of the three sides of the triangle:
Suppose we know the values of the three sides a, b and c of the triangle.
If s is the semiperimeter of the triangle, that is, s = $\frac{a+b+c}{2}$, then:

$Area=\sqrt{s(s-a)(s-b)(s-c)}$

 Find the area of triangle from a = 4, b = 6 and c = 4 using heron's formula.

$Area=\sqrt{s(s-a)(s-b)(s-c)}$

s = $\frac{a+b+c}{2}$ = $\frac{4+6+4}{2}$ = 7

$Area=\sqrt{s(s-a)(s-b)(s-c)}$ = $\sqrt{7(7-4)(7-6)(7-4)}$ = 7.94

Find the area of the triangle where:
the height is 4the base is 8
Area=