Perimeter divided by base??
Answer: 250 m
Step-by-step explanation:
Given
Distance between Ursula and Velda house is 4 km or 4000 m
Ursula walks at the rate of 
Velda walks at the rate of 
Time taken by them to cover 4000 m is

Distance covered by them 15 min before they meet
Ursula 
Velda 
The total length covered by them is 
They are
apart before they meet
2,953.54 * 10^21 kg
https://www.quora.com/What-is-the-average-mass-of-the-rocky-planets-in-our-solar-system
The answer is 12.5 km/hr
45/3.6=12.5