Answer:
[tex]\sf Area\:of\:a\:triangle=\dfrac12 \times base \times height[/tex]
Given:
- area = 18 cm²
- base = 6 cm
- height = (h + 1) cm
Substitute the given values into the equation and solve for h:
[tex]\sf \implies 18 = \sf \dfrac12 \times 6 \times (h+1)[/tex]
[tex]\sf \implies 18 = \sf \dfrac62 (h+1)[/tex]
[tex]\sf \implies 18 =3(h+1)[/tex]
expand using distributive property of addition [tex]a(b+c)=ab+ac[/tex]:
[tex]\sf \implies 18=3h+3[/tex]
subtract 3 from both sides:
[tex]\sf \implies 3h=15[/tex]
divide both sides by 3:
[tex]\sf \implies h=5[/tex]
To verify:
Half of the base is 3 cm.
If h=5, then the height of the triangle is 6 cm.
Multiplying 3 by 6 is 18.
This matches the given area, so we can verify that h = 5.