Answer:
77. Proved
78. Proved
79. Proved.
80. Proved.
Step-by-step explanation:
77. Left hand side
=
{Since we know, }
= Right hand side (Proved)
78. Left hand side
{Since }
79. Left hand side
= Right hand side
80. Left hand side
= Right hand side. (Proved)
Answer: the answer is D
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12 inches
should be 70!!!!!!!!!!!!!!