Answer:
19.595 units²
Explanation:
Find length of other sides:
An isosceles triangle has 2 sides equal. It has two 45 degrees angles and one 90 degrees angle. We can use Pythagorean theorem.
The 2 equal sides measure 4 units.
Find area:
base × height × 1/2
The height can be found by Pythagorean theorem.
height² = 4² + 4sqrt(2)²
height² = 16 + 32
height² = 48
height = 6.928
base is given
4sqrt(2) × 6.928 × 1/2
= 19.595343