Solution: For finding QR we need to apply Pythagoras Theorem
What is Pythagoras Theorem ?
ans : Pythagoras Theorem is the sum of square of two sides which is equal to the third side or the hypotenuse. This formula is valid oy incase of Right-Angled Traingle because one of three angles here is 90°
According to this law let's apply it in the diagram shown here.
- (Hypotenuse)² = (Adjacent)² + (Opposite)²
- (5x - 2)² = (QR)² + (3x - 1)²
- (QR)² = (5x - 2)² - (3x - 1)²
After factorising both of them we get
- (QR)² = 25x² - 20x + 4 - (9x² - 6x + 1)
- (QR)² = 25x² - 20x + 4 - 9x² + 6x - 1
So, QR is √(16x² - 14x + 3)
