area of isosceles triangle

ketkoag wrote:Guys, please lemme know how to calculate the area of an isosceles triangle if two of its sides and one angle are given. None of the angles are right angle.. I came across such question a few days back but can't remember it now..
Please help me with this; how to solve it or any standard formula for the same?

Hi Ket, can you provide some numbers?

There could be some ways to solve this problem in a GMAT context, but having the value of the angle and the sides helps.

Sincerely,
Musiq

Area of an isosceles triangle = b/4 *[sqrt(4a^2 -b^2)]

Height of an isosceles triangle = 1/2 *[sqrt(4a^2 -b^2)]

b = base

a = one of the equal sides


Hope this helps.

ketkoag wrote:Guys, please lemme know how to calculate the area of an isosceles triangle if two of its sides and one angle are given. None of the angles are right angle.. I came across such question a few days back but can't remember it now..
Please help me with this; how to solve it or any standard formula for the same?

On the GMAT, you definitely do not need to know the formula above - you just need to know the pythagorean theorum (from which the formula is derived).

You also don't need to know any trigonometry, so unless the angle is 30, 60 or 45 (angles which would lead to special right triangles and shortcuts to identifying the height) it's unlikely to be relevant to your calculation; the main purpose of that angle will be to allow you to conclude which of the two sides is duplicated.

thanks a lot for your help..