Calculate the area of triangle cde with altitude ef, given c (3, −2), d (−1, 2), e (2, 3), and f (0, 1). 4 square units 6.2 square units 8 square units 8.7 square units

8 square units

Step-by-step explanation:

taking angle EFC to be 90 degrees

the area of triangle CDE is given as

Area = 1/2(CD x EF)

distance between two point is

√(x2 - x1)² + (y2 - y1)²

distance CD = √(-1-3)²+(2-(-2))² = √32 units

distance EF = √(2-0)²+(3-1)²=√8units

Area CDE = 1/2(√32 x √8) = 8.00 square units

8 square units.

Step-by-step explanation:

In order to calculate the area of a triangle you need to know what the formula is to find the area. The area formula for a triangle is 1/2bh

Area = 1/2(base)(height)

The Area = 1/2 x

8 = 1/2 x

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form

a_n = a_1 + (n - 1)d

the first term is 6.

the common difference d = ?

when you find d, replace n with 7 and d with the common difference to find your answer.