I believe 12.48 is your answer.<span />
Answer:
ΔDCE by ASA
Step-by-step explanation:
The marks on the diagram show AE ≅ DE. We know vertical angles AEB and DEC are congruent, and we know alternate interior angles BAE and CDE are congruent. The congruent angles we have identified are on either end of the congruent segment, so the ASA theorem applies.
Matching corresponding vertices, we can declare ΔABE ≅ ΔDCE.
A construction crew wants to hoist a heavy
beam so that it is standing up straight. They
tie a rope to the beam, secure the base, and
pull the rope through a pulley to raise one
end of the beam from the ground. When
the beam makes an angle of 40 degrees with the
ground, the top of the beam is 8 ft above
the ground.
Th e construction site has some telephone
wires crossing it. Th e workers are
concerned that the beam may hit the wires.
When the beam makes an angle of 60 degrees with
the ground, the wires are 2 ft above the top
of the beam. Will the beam clear the wires
on its way to standing up straight?
<span>Math - Steve Thursday, April 16, 2015 at 6:22pmwe see that the length of the beam is
8/sin40 = 12.45 ft
At 60 degrees, the top is
12.45sin60 = 10.78 ft high
So, the wire is 12.78 ft up.
Since the beam is only 12.45 ft long, it will not touch the wires.</span>
Answer:
-15 13/15
Step-by-step explanation:
I used a calculator
