Whakaoti i te 10^2+20^2-2(10)(20)cos(60)

$${ 10 }^{ 2 } + { 20 }^{ 2 } -2(10)(20) \cos ( 60 )$$

Aromātai

$$300$$

Ngā Upane Otinga

Tātaihia te 10 mā te pū o 2, kia riro ko 100.

$$100+20^{2}-2\times 10\times 20\cos(60)$$

Tātaihia te 20 mā te pū o 2, kia riro ko 400.

$$100+400-2\times 10\times 20\cos(60)$$

Tāpirihia te 100 ki te 400, ka 500.

$$500-2\times 10\times 20\cos(60)$$

Whakareatia te 2 ki te 10, ka 20.

$$500-20\times 20\cos(60)$$

Whakareatia te 20 ki te 20, ka 400.

$$500-400\cos(60)$$

Tīkina te uara \cos(60) mai i te ripanga uara pākoki.

$$500-400\times \frac{1}{2}$$

Whakareatia te 400 ki te \frac{1}{2}, ka 200.

$$500-200$$

Tangohia te 200 i te 500, ka 300.

$$300$$