Question

In a triangle ABC, AC = 12 cm , AB = 6√3cm , BC = 6cm . Then find angle B ?

plz solve fast with easy method .I will mark brainlist​

Answer 1

Answer: 90°

Given,

In a triangle ABC,

AC = 12 cm, AB = 6√3cm, BC = 6cm.

To find out,

< B = ?

Solution:

Here,

${AB}^{2} + {BC}^{2} \\ \\ = ({6 \sqrt{3}) }^{2} + {(6)}^{2} \\ \\ = 36 \times 3 + 36 \\ \\ = 108 + 36 \\ \\ = 144$

${AC}^{2} = {12}^{2} = 144$

Here by pythagoras theorem AC^2 = AB^2+BC^2.

So, we can say that it is a right angled triangle. Hence <B = 90°.

Proof:

${12}^{2} = {(6 \sqrt{3}) }^{2} + {6}^{2} \\ \\ 144 = 36 \times 3 + 36 \\ \\ 144 = 108 + 36 \\ \\ 144 = 144$