Question

AD is drawn perpendicular to base BC of an equilateral triangle ABC. Given BC= 10 cm , find the length of AD , correct to 1 place of decimal.

Answer 1

Okay Mate lets Check your answer

The given Traingle is a Equilateral triangle , hence all Sides are Equal
AB = BC = AC = 10 cm

BD = 1/2 × BC
= 1/2 × 10 = 5cm
THEOREM = Any line drawn perpendicular to the opposite side is an equilateral triangle bisects the opposite side

Hence According to the Pythagoras Theorem

$(ab) {}^{2} = (ad) {}^{2} + (bd) {}^{2}$
$10 {}^{2} = ad {}^{2} + 5 {}^{2}$
$(ad) {}^{2} = 100 \: - 25$
$(ad) {}^{2} = 75$
AD = 5√3

Hence your answer The length of AD = 5√3

Hope it helps