Equate the sum of the angles' expressions with the sum of the interior angles of a pentagon.
4/5
Practice makes perfect
Let's first find the measure of each angle. To determine the sum of the interior angles in a polygon, we use the formula 180^(∘)(n-2) where n is the number of sides.
When we know that x= 30^(∘) we can find the measure of each angle.
3( 30^(∘))-26^(∘)& = 64^(∘)
2( 30^(∘))+70^(∘)& = 130^(∘)
5( 30^(∘))-10^(∘)& = 140^(∘)
3( 30^(∘))& = 90^(∘)
2( 30^(∘))+56^(∘)& = 116^(∘)
As we can see, 4 of 5 angles are greater than or equal to 90^(∘). Therefore, the probability of selecting an angle that is more than or equal to 90^(∘) must be 4 5.
