If R and T are rise and tread of a stair spanning horizontally, the steps are supported by a wall on one side and by a stringer beam on the other side, the steps are designed as beams of width
A
R + T
B
T - R
C
$$\sqrt {{{\text{R}}^2} + {{\text{T}}^2}} $$
D
R - T
Correct Answer: $$\sqrt {{{\text{R}}^2} + {{\text{T}}^2}} $$