Question

Can someone help me on this

Answer 1

130

Explanation:

Since we know all three angles on a triangle added together equals 180 and it is also a rule that if an angle is split like this is here on a straight line those added together to equal 180

So we know the exterior angle will be equal to the sum of those two angles in the triangle

So we set up an equation like this

`10x+10=50+5x+20\\`

Simplify

`10x+10=5x+70`

Subtract 10 on both sides

`10x=5x+60`

Subtract 5x on both sides

`5x=60`

Divide both sides by 5

`x=12`

Now that we know x we can find angle YST by filling in x

`10(12)+10\\120+10\\130`

Angle YST is equal to 130

Hope this helps please let know if you have further questions