Question

The vertical angle of an isosceles triangle measure $(5t-18{)}^o$ and one of the base angles measure $3t^o$. The value of $t$ is

• A. $15$
• B. $24$
• C. $18$
• D. $12$

Answer 1

The correct option is C $18$

Given the vertical angle of and isosceles triangle is $(5t-18{)}^o$ and the base angles are $3t^o,3t^o$. [ Since the base angles are same]

Then,

$5t^o-{18}^o+3t^o+3t^o={180}^o$

or, $11t^o={198}^o$

or, $t=18$.