Area of a triangle is 1/2 base times height. the base is the horizontal part of the triangle and the height is the vertical part. Since it a isosceles they are equal. Those two segment are also called the legs (remember that for later). 4x4=16 times 1/2 equal 8 cm squared. So know me must find the hypotenuse. Since we since dealing with a right triangle we are going to use pythagorean theorem which is
where a and b are the LEGS and c is the hypotenuse. the legs are also known as base and height so we use