Your answer will be B because since the base is 4 you need to multiply it with something that will divide by 2 and equal 20. so 4x10=40 and 40/2=20 so b is your answer

DelanaDavolt802

The length of the base of a right triangle would be 10. Because 10x4 would equal to 40 and divide that by 2 would equal 20, which is the area. Area= h x b/2