The area of a triangle is 21ft². If the height of the triangle is 7ft, how long is the base of the triangle? Please give your answer and explain how you found it.

The answer is b = 6

Step-by-step explanation:

Area of a triangle= 1/2 × b × h

A = 21, h = 7, b = ?

21 = 1/2 × b × 7 (multiplying through)

21 = 7b/2

Cross multiply

2 × 21 = 7b

42 = 7b

b = 42/7

b = 6

b = 6ft

Step-by-step explanation:

Area of a triangle = 1/2 x base x height

Given the area = 21ft^2

Height = 7ft

Base = ?

Using the above formula

21 = 1/2 x b x 7

21 = 7b/2

Cross multiply

7b = 21 x 2

7b = 42

Divide both sides by 7

7b/7 = 42/7

b = 6ft

The length of the base is 6ft

  y= -3x is the required function.

step-by-step explanation:

we have been given a table:

x             y

0             0

1             -3

3             -9

-2             6

we can see that the values of y is -3 times the value of x

hence, the function would be: y= -3x.

put the values of x will give the same y as in the table that means function is satisfying the given table.