Answer:
alright I can help!
for 20: let's first say the equation to figure out if it is a right triangle (the pythagorean theorem). so a^2 + b^2 = c^2 -> 2^2 + 2^2 =3^2 -> 4+4=9 does not equal out so 20 is not a right triangle.
for 27: the equation for area is (height×base)/2 -> (2×4)/2 -> area = 4
for 29: so let's find the circumference first. the equation is 2× pi × r -> 2× pi × 5 -> circumference = 10pi or about 31.42.
so now we can find the area of the circle. the equation is pi × r^2 -> pi × 5^2 -> area of circle= 25pi or about 78.54
hope this helps!! best wishes and best of luck!