Question

Find the area of an isosceles triangle,the measure o its equal sides being b and its third side a

Answer 1

Step-by-step explanation:

Base = a

Same sides = b

In isosceles triangle ABC ,

AD is perpendicular to BC .

AB = AC = b

BC = a

height = AD

In right angled triangle ABD ,

AB² = AD² + BD²

AD² = AB² - BD²

= (b)² - (a/2)²

= b² - a²/4

AD = √(4b² - a²)/4

= 1/2 * √4b² - a²

Area of this isosceles triangle

= 1/2 * base * height

= 1/2 * a * 1/2 √4a²-b²

= (a/4)* √4b²-a²

= a√4b²-a² / 4