First use Pythagoras theorem to find the remaining length of the base. Then multiply the base with the altitude and divide that by 2 and you'll get the area
Answer: To find the third side of a triangle (there are two answers you could get), you need to use the Pythagorean formula: a^2+b^2=c^2. First answer, 3^2+5^2=c^2. Solve for c. c=5.83. The second answer, 3^2+b^2=5^2. Solve for b. b=4.
