Considere um triângulo retângulo, cujos ângulos agudos a e b satisfazem à condição cos a = 0,8 e cos b = 0,6 Determine a área desse triângulo, em cm² sabendo que o comprimento da hipotenusa é 5 cm. a) 4,5
b) 6
c) 7,5
d) 8
e) 10

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles.

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Asif spent $745.10 on 13 new file cabinets for his office. small file cabinets cost $43.50 and large file cabinets cost $65.95. write and solve a system of equations to find the number of small cabinets and large cabinets he purchased. determine if each statement is true or false. 1. he purchased 5 small cabinets. true or false 2. he purchased 7 large cabinets. true or false 3. he spent $527.60 on large cabinets. true or false