Inscribed Angles
1. **State the problem:** Understanding the properties of inscribed angles and intercepted arcs in a circle based on given theorems and angle measures.
2. **Theorem 1:** The measure of an inscribed angle equals half the measure of its intercepted arc.
Given: $AT=120^\circ$, intercepted arc $LACT=60^\circ$.
This matches the theorem since $\frac{1}{2}\times 120^\circ = 60^\circ$.
3. **Theorem 2:** Two inscribed angles intercepting congruent arcs are congruent.
Given: $LI=95^\circ$, $LL=35^\circ$ and $LI\cong LL$.
Since $95^\circ \neq 35^\circ$, angles $LI$ and $LL$ cannot be congruent unless their intercepted arcs are equal;
this suggests an error or different arcs intercepted by $LI$ and $LL$, or angle measures differ from arcs.
4. **Theorem 3:** An inscribed angle intercepting a semicircle is a right angle ($90^\circ$).
Given: $LNTIE=90^\circ$ confirms this.
Also, $NE=45^\circ$ is provided but not relevant here.
5. **Theorem 4:** Opposite angles of a cyclic quadrilateral sum to $180^\circ$ (are supplementary).
Given angles sums:
$LRDA + LKEA = ?$
$LPRA + LDAE = ?$
By the theorem,
$$ LRDA + LKEA = 180^\circ $$
$$ LPRA + LDAE = 180^\circ $$
**Summary:**
- Use $m(\text{inscribed angle}) = \frac{1}{2} m(\text{intercepted arc})$
- Congruent arcs subtend congruent angles
- Angles intercepting a semicircle are right angles
- Opposite angles in cyclic quadrilaterals are supplementary
Thus:
- $60^\circ$ is half of $120^\circ$ intercepted arc
- If two inscribed angles intercept congruent arcs, then they are congruent
- $LNTIE=90^\circ$ corresponds to interception of a semicircle
- $LRDA + LKEA = 180^\circ$, $LPRA + LDAE = 180^\circ$.
Final answers are the theorem applications stated.