Question

in ∆ABC,B=90°,AC=5cm,and BC=4cm find AB​

Answer 1

ABC is a right angled triangle
Using Pythagorean’s theorem

AC^2 =AB^2 +BC^2
5^2 = AB^2 + 4^2
25=AB^2+16
25-16=AB^2
9=AB^2
AB=3cm

I hope it will help you

Answer 2

GIVEN :-

• In △ABC , ∠B = 90°.
• AC = 5 cm.
• BC = 4 cm.

TO FIND :-

• AB.

SOLUTION :-

∵ In △ABC , ∠B = 90°, Therefore It is a right angled triangle.

◉ Hypotenuse (AC) = 5 cm.

◉ Base (BC) = 4 cm

◉ Perpendicular (AB) = ?

☯ BY PYTHAGORAS THEOREM,

➫ (Hypotenuse)² = (Base)² + (Perpendicular)²

➫ AC² = BC² + AB²

➫ (5)² = (4)² + AB²

➫ 25 = 16 + AB²

➫ AB² = 25 - 16

➫ AB² = 9

➫ AB = √9

➫ AB = 3

Hence the Perpendicular (AB) = 3 cm.

VERIFICATION :-

➫ (Hypotenuse)² = (Base)² + (Perpendicular)²

➫ AC² = BC² + AB²

➫ 5² = 4² + 3²

➫ 25 = 16 + 9

➫ 25 = 25

L.H.S = R.H.S

HENCE VERIFIED ✔