Question

In a right-angled triangle ABC, if B = 90°, BC = 3 cm and AC = 5 cm, then find length of side AB

Answer 1

Answer:

4 cm

Step-by-step explanation:

Hypotenuse(AC) = 5 cm

Base(BC) = 3 cm

Perpendicular(AB)^2 = (AC)^2 - (BC)^2

=> 5^2 - 3^2 = 25 - 9= 16

AB = sq.root(16) = 4 cm

Answer 2

Answer:

4 cm

Step-by-step explanation:

We know that :

a^2 + b^2 = c^2 (where c is the hypotenuse and a and b are the sides) ...... (1)

In the given triangle,

the hypotenuse = 5 cm (c)

one of the sides = 3 cm (b)

then, a = ?

from (1):

a = $\sqrt{c^{2} - b^{2}}$

  =$\sqrt{5^{2} - 3^{2} }$

  =$\sqrt{16}$

  =4 cm