Hi there!

We can begin by finding ∠VUY so we can solve for ∠UVY.
∠VUY is supplementary to ∠TUY, so:
180 = 144 + ∠VUY
∠VUY = 36°
In a triangle, angles sum up to 180°, so:
180 = 36° + 79° + m∠UVY
m∠UVY = 65°
Solve for m∠VYZ by comparing the angle to m∠UVY because the angles are alternating interior angles. Thus:
m∠UVY = m∠VYZ = 65°.
Answer:
1.67 hours
Step-by-step explanation:
Let the original speed of Jonathan =
units/hr
Let the original time taken by Jonathan =
hours
Let the distance =
units
Formula for distance is given as:

Given that half the distance is covered by original speed.

Half the distance is covered by increasing the rate by 25%.
i.e. increased speed:

Hence, Time taken:

Distance traveled is half of the total distance:

Dividing (1) by (2):
