Answer:
dA/dt = 31 in²/ sec
Step-by-step explanation:
The area of the triangle is:
A(t) = (1/2)*b*h where b is the base and h the height
Differentiation on both sides of the equation we obtain
dA/dt = (1/2)* db/dt * h + (1/2)* dh/dt * b (1)
db/dt = 3 in/sec
dh/dt = 2 n/sec
b = 10 in
h = 14 in
By substitution in (1)
dA/dt = 0,5* 3*14 + 0,5* 2*10
dA/dt = 21 in² /sec + 10 in²/sc
dA/dt = 31 in²/ sec
