91Ó°ÊÓ

If ∠BOC is a right angle and $\mathrm{m}∠\mathrm{COD}=58$, then $\mathbf{m}∠\mathrm{DOE}=\underset{¯}{?}$, $\mathbf{m}∠\mathrm{BOA}=\underset{¯}{?}$and data-custom-editor="chemistry" $\mathbf{m}∠\mathrm{AOC}=\underset{¯}{?}$.

Classify each statement as true or false.

$\stackrel{↔}{WV}$intersects the plane ABGF.

In the diagram, $∠AFB$is a right angle. Name the figures described.

Two obtuse vertical angles.

In the diagram,$\stackrel{→}{BE}âŠ\yen \stackrel{↔}{AC}$ and $\stackrel{→}{BD}âŠ\yen \stackrel{→}{BF}$. Find the value of x.

$m∠ABD=6x$, $m∠DBE=3x+9$, $m∠EBF=4x+18$, $m∠FBC=4x$

Write the name or statement of the definition, postulate, or theorem that justifies the statement about the diagram.

If ∠4 is complementary to ∠5 and ∠6 is complementary to ∠5 then $∠4â‰\dots ∠6$.

Write a proof in two-column form.

Given: $\stackrel{\mathit{↔}}{\mathit{\text{DC}}}\mathit{âŠ\yen }\stackrel{\mathit{↔}}{\mathit{\text{BD}}}$; $∠\mathbf{1}â‰\dots ∠\mathbf{2}$.

Prove:$\stackrel{\mathit{↔}}{\mathit{\text{BA}}}\mathit{âŠ\yen }\stackrel{\mathit{↔}}{\mathit{\text{BD}}}$

Complete.

$∠FOBâ‰\dots \underset{¯}{?}$

Copy and complete the proof of Theorem 2-6: If the exterior of two adjacent acute angles is perpendicular, then the angles are complementary.

Given:$\stackrel{→}{OA}âŠ\yen \stackrel{→}{OC}$

Prove: $∠AOB$and $∠BOC$are comp. $∠s$.

Proof:

Complete.

$∠COAâ‰\dots \underset{¯}{?}$

Copy everything shown and write a two-column proof.

Given:$RQ=TP;$

$ZQ=ZP$

Prove:$RZ=TZ$