Answer:
54 cm
Step-by-step explanation:
The area (A) of an equilateral triangle is
A = ( s is the side length ) then
= 81
( multiply both sides by 4 to clear the fraction )
s² = 324
( divide both sides by
)
s² = 324 ( take the square root of both sides )
s = = 18
Thus
perimeter = 3 × 18 = 54 cm
Answer:
The y-coordinate of their intersection point is 3
That is y=3
Step-by-step explanation:
Given two lines are y=6x+15 and y=mx+4
Given that the two lines intersect at x=-2
To find the y coordinate of their intersection point :
Equating the two lines
6x+15=mx+4
6x+15-mx-4=0
6x-mx+11=0
(6-m)x+11=0
At x=-2 (6-m)x+11=0
(6-m)(-2)+11=0
(6-m)(-2)=-11
Substitute the value in y=mx+4 we get
At x=-2
Therefore y=3
Therefore the y-coordinate of their intersection point is 3