Answer:

Explanation:
given,
refractive index of lens, n = 1.70
Radius of curvature of front surface. R₁ = 20 cm
Radius of curvature of the back surface, R₂ = 30 cm
focal length= ?

R₁ = +20 cm
R₂ = -30 cm
n = 1.70




the focal length of the lens is equal to 17.15 cm
Answer:
163.8 ft
Explanation:
In triangle ABD
= 155 ft


Using Pythagorean theorem in triangle ADC

= distance between the anchor points
distance between the anchor points is given as

They has been very successful but they are very expensive to operate that is your answer I hope this helps