You can also use heron’s formula to find area of the triangle no need height. Do you know that formula check it out . And area you sure the height is 8??. If three sides given you have calculate the height .
Please solve the question : if you can An isoceles traingle with its equal sides are 10.5 cm which is also the radius of a circle. Make sure that the traingle is inside the circle. Find the perimetre of traingle?????? I think you can not solve