In a right △ABC, CD (D ∈ AB) is the angle bisector of the right ∠C. Two segments, DF (F ∈ AC) and DE (E ∈BC) are drawn parallel to the legs of the triangle. Prove that DFCE is a square.
m∠CED = 180° − m∠= by reason
m∠CFD = 180° − m∠= by reason

m∠CED = 180° − m∠ ECF = 90° by reason Same Side Interior Angles

m∠CFD = 180° −  m∠ ECF = 90° by reason Same Side Interior Angles

Step-by-step explanation:

You an see that they gave you parallel lines in DFCE. You can use these to input parallel line contingencies. You can then prove, using Same Side Interior  Angles, that angle CED and angle CFD are 90 degrees, making the shape a square as well. Hope this helped :)

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.