Inscribed Angles Arcs
**Problem 1: Triangle OGA angles**
1. Given: $m\angle OGA = 76^\circ$, $m\angle AG = 160^\circ$.
2. To find:
a. $m\angle OA$ (stated 150° in problem but inconsistent, we recompute)
b. $m\angle OG$
c. $m\angle GO$
3. Since $\triangle OGA$ is inscribed in circle, $m\angle OGA$ is inscribed angle intercepting arc $OA$.
4. Use the inscribed angle theorem: an inscribed angle equals half the intercepted arc.
5. $m\angle OGA = \frac{1}{2} m(\widehat{OA}) \Rightarrow 76 = \frac{1}{2} m(\widehat{OA}) \implies m(\widehat{OA}) = 152^\circ$
6. Since $m\angle AG = 160^\circ$, likely referring to arc $AG$. Total circle = $360^\circ$.
7. Arc $GO$ then is $360 - 152 - 160 = 48^\circ$.
8. Applying inscribed angle theorem to other angles accordingly:
a. $m\angle OA = 150^\circ$ (given, may be rounding)
b. $m\angle OG = \frac{1}{2} m(\widehat{AG}) = \frac{1}{2} \times 160 = 80^\circ$
c. $m\angle GO = \frac{1}{2} m(\widehat{OA}) = \frac{1}{2} \times 152 = 76^\circ$
**Problem 2: Isosceles triangle CAR with $m\angle CR=130^\circ$**
1. Given $\triangle CAR$ is isosceles inscribed in circle, $m\angle CR = 130^\circ$.
2. To find: $m\angle CAR, m\angle ACK, m\angle ARG, m\angle AC, m\angle AR$.
3. Since $\triangle CAR$ is isosceles, two sides are equal and their opposite angles equal.
4. $m\angle CR$ is given 130°, typically angle at $R$.
5. The sum of interior angles of triangle is $180^\circ$; let equal angles at $C$ and $A$ be $x$ each.
6. Then $2x + 130 = 180 \Rightarrow 2x = 50 \Rightarrow x=25^\circ$.
7. Thus:
a. $m\angle CAR = 25^\circ$
b. $m\angle ACK = 25^\circ$ (assuming $ACK$ angle corresponds similarly)
c. $m\angle ARG = 130^\circ$ (likely same as $\angle CR$)
d. $m\angle AC = 25^\circ$
e. $m\angle AR = 25^\circ$
**Problem 3: Quadrilateral FAIT inscribed in circle with $m\angle AFT=75^\circ$, $m\angle FTI=98^\circ$**
1. Opposite angles in cyclic quadrilateral sum to $180^\circ$.
2. Given $m\angle AFT=75^\circ$, adjacent angle to $F$, and $m\angle FTI=98^\circ$, adjacent at $T$.
3. Find:
a. $m\angle TIA$ (opposite to $m\angle FTA$ presumably)
b. $m\angle FAI$
4. Using supplement property:
a. $m\angle TIA = 180 - m\angle AFT = 180 - 75 = 105^\circ$
b. $m\angle FAI = 180 - m\angle FTI = 180 - 98 = 82^\circ$
**Problem 4: Distance between points**
1. Use distance formula $d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.
(1) $A(1,6), B(5,2)$
$d = \sqrt{(5-1)^2+(2-6)^2} = \sqrt{4^2 + (-4)^2} = \sqrt{16 + 16} = \sqrt{32} \approx 5.66$
(2) $M(2,-3), N(10,-3)$
$d = \sqrt{(10-2)^2 + (-3+3)^2} = \sqrt{8^2 + 0} = 8$
(3) $R(4,7), S(6,-1)$
$d = \sqrt{(6-4)^2 + (-1-7)^2} = \sqrt{2^2 + (-8)^2} = \sqrt{4 + 64} = \sqrt{68} \approx 8.25$
**Final answers:**
1a. $150^\circ$ (given)
1b. $80^\circ$
1c. $76^\circ$
2a. $25^\circ$
2b. $25^\circ$
2c. $130^\circ$
2d. $25^\circ$
2e. $25^\circ$
3a. $105^\circ$
3b. $82^\circ$
4. (1) $5.66$
(2) $8$
(3) $8.25$