Question

Find area of traingle ABC in which angle ABC=90 and angle ACB=45 and AC=6cm

Answer 1

by pythagorean theorem:
x^2+x^2=6^2
2x^2=36
x^2=6cm
area of right angles and isosceles triangle is:
=x^2/2
=18/2
=6cm^2

Answer 2

Well it's an very easy questions
In ∆ABC
angle A + angle B + angle C = 180°
angle A = 45°= angle C...............(i)
From (i) we can say that:
AB = AC .................(ii)
From Pythagoras theorem
${(ab)}^{2} + {(bc)}^{2} = {(ac)}^{2}$
We know that AC = 6CM
From (ii) we can conclude that
AB = AC = √18cm
Area of ∆ABC = 0.5 X B X H
= 0.5 X √18 X √18
= 9 cm^2