The answer to the first part is D
Answer: Triangle QRS is an isosceles triangle because QR = RS.
. Step-by-step explanation: Find the length of each side of the triangle using the formula for calculating the distance between two points.
Step-by-step explanation:
Answer:
16√3 cm²
Step-by-step explanation:
The perimeter of a triangle is the sum of its all three sides. Since this is an equilateral triangle, all sides are equal.
Let's consider one side of the triangle to be 'x'
Givent that, the perimeter is 24cm,
The equation should be x + x + x = 24
⇒3x = 24
∴ x = 8 cm
To find the area of the triangle, we need to find the height, and for that, we can use trigonometry.
Since it is an equilateral triangle, all angles are exact 60°.
let's draw a line and mark it as 'h'.
we can use sine formula to find out the opposite i.e. h
sin∅ = opposite ÷ hypotaneous
sin 60° = h ÷ 8
h = 8 sin 60°
h= 4√3
Now, let's find the area
Area = 1/2 × base × height
Area = 1/2 × 8 × 4√3
area= 16√3 cm²
Answer: X=-1
Step-by-step explanation:
Answer:
Speed of the river =
km per hour
Step-by-step explanation:
Speed of the boat in still water = 4 km per hour
Let the speed of the river = v km per hour
Speed of the boat upstream = (4 - v) km per hour
Time taken to cover 6 km = 
=
hours
Speed of the boat downstream = (4 + v) km per hour
Time taken to cover 12 km =
hours
Since, time taken by the boat in both the cases is same,

6(4 + v) = 12(4 - v)
24 + 6v = 48 - 12v
12v + 6v = 48 - 24
18v = 24
v = 
v =
km per hour