Answer:
a² + b² = 22
Step-by-step explanation:
(a + b)² = a² + 2ab + b² ← substitute a + b = 6 and ab = 7
6² = a² + 2(7) + b²
36 = a² + 14 + b² ( subtract 14 from both sides )
22 = a² + b²
Let A be the surface area, b the base, h the height;
h₁=8.4 cm
h₂=7.8 cm
b= 9 cm
A= 3(1/2bh₁)+1/2 bh₂
A=3(1/2(9)(8.4))+1/2 (9)(7.8)
A= 148.5 cm³
Answer:
4√5
Step-by-step explanation:
Use Pythagorean theorem
a^2=21^2-19^2
a^2=441-19^2
a^2=441-361
a^2=80
a= √80
simplify
