Step-by-step explanation: there are twenty squares so 20 will be your denominator and six are shaded so 6 will be your numerator so it will be 6/20 or you could simplify the fraction to 3/10 because you divided both your numerator and denominator by 2 which is allowed in math problems
A given angle measures 90°.. Then, note that the total measurement of the triangle is 180°... Subtract 180° by 90°, and the other angles must add up to 90°!