The lengths of the sides of a triangle are 5 m, 5 m and 8 m. What is the area of the triangle?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 12 m2
The triangle is isosceles (two sides of 5 m), so the height drawn to the 8 m base falls on its midpoint and splits it into two right-angled triangles.
Each half of the base: \(8\div2=4\) m
Height, by Pythagoras in one right triangle: \(\sqrt{5^2-4^2}=\sqrt{25-16}=3\) m
Area, half the base times the height: \(\displaystyle\frac{1}{2}\times8\times3=12\) m2