Solve 10^2+20^2-2(10)(20)cos(60)

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

Evaluate

$$300$$

Solution Steps

Calculate 10 to the power of 2 and get 100.

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

Calculate 20 to the power of 2 and get 400.

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

Add 100 and 400 to get 500.

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

Multiply 2 and 10 to get 20.

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

Multiply 20 and 20 to get 400.

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

Get the value of \cos(60) from trigonometric values table.

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

Multiply 400 and \frac{1}{2} to get 200.

$$500-200$$

Subtract 200 from 500 to get 300.

$$300$$