Angles of Elevation and Depression are used in measuring heights and distances in trigonometric applications using right triangles. These angles are made when we look up or down to view objects. Devices are available to measure angles of elevation and depression. These measured angles can be used in measuring heights and distance which are either tedious or impractical to measure, by modelling the situation into right triangles
Answer:
<u> BC = 10 and AD = 30</u>
Step-by-step explanation:
In figure-1 , AB = CD ,BK ⊥ AD, AK = 10, KD = 20.
Since, line AD is sum of AK and KD, then
AD = AK + KD
AD = 10 + 20
AD = 30
Since, BC ║AD and BK ⊥ AD then similarly we construct CL ⊥ AD
so, BC = KL and AK = LD
KL = AD - LD
KL = 20 - 10
KL = 10
Since, BC = KL then BC = 10
Hence, <u> BC = 10 and AD = 30</u>
They would have to sell around a 1000 newspapers
<span>8(-9-5x)
</span>=8(-9) - 8(5x)
= -72 - 40x
= - 40x - 72
expand by using distributive property
hope it helps