Question

Jika oa = 2cm dan cb = 7cm. maka luas bidang oabc adalah...
a.4√5
b.5√5
c.6√5
d.7√5

Answer 1

Cb =√7² - 2²
cb = √ 49 - 4
cb = √45
cb = 3√5

luas OABC
= 2 . luas ∆
= 2 . ½ . alas . t
= 2 . ½ . 2 . 3√5
= 6√5