It takes Gretchen 275 seconds to travel 5500 m in her car. What is her rate of speed in kilometers per hour

72km/h

Step-by-step explanation:

Convert units to kilometers and hours.

275 seconds ÷ 60² ≈ 0.0764 hours

5500 meters ÷ 1000 = 5.5 km

Convert to kilometers/hour.

5.5km ÷ 0.0764hrs = 72km/h

answer:   the paragraph proof is mentioned below.

step-by-step explanation:

given: in a δxwy where

such that, ∠wzx ≅ ∠yzx and zw≅zy

we have to prove that: segment zx is a perpendicular bisector of segment wy.

prove: since, zw≅zy ⇒ ∠wzy is a supplementary angle.

then, ∠wzy= 180°

⇒∠wzx + ∠yzx = 180° ( because xz divides ∠wzy into two parts)

but, ∠wzx ≅ ∠yzx ( given)

⇒∠wzy+∠wzy=180° ( by substitution)

⇒2∠wzy=180°

⇒∠wzy=90°

⇒∠wzy=∠yzx =90°

therefore, xz⊥wy where wz=zy

⇒zx is a perpendicular bisector of wy.