Answer:
a square backyard with width (x - 9)
Step-by-step explanation:
x²−18x + 81 = x² - (2 x 9) x + 9² = (x - 9)²
width = area / length = (x - 9)² / (x - 9) = x - 9
Length = width
This is a square backyard
Answer:
200
Step-by-step explanation:
Step-by-step explanation:
5x-7+3x+27=180
8x+20=180
8x=160
x=20°.
hope this helps you.
Question is Incomplete, Complete question is given below.
Prove that a triangle with the sides (a − 1) cm, 2√a cm and (a + 1) cm is a right angled triangle.
Answer:
∆ABC is right angled triangle with right angle at B.
Step-by-step explanation:
Given : Triangle having sides (a - 1) cm, 2√a and (a + 1) cm.
We need to prove that triangle is the right angled triangle.
Let the triangle be denoted by Δ ABC with side as;
AB = (a - 1) cm
BC = (2√ a) cm
CA = (a + 1) cm
Hence,
Now We know that

So;


Now;

Also;

Now We know that




[By Pythagoras theorem]

Hence, 
Now In right angled triangle the sum of square of two sides of triangle is equal to square of the third side.
This proves that ∆ABC is right angled triangle with right angle at B.