Question

1.InarightangledtriangleABC,<ABC=90⁰,AB=15cmandBC=8cm.FindsinA,cosAandtanA​

Answer 1

✪ᴀɴsᴡᴇʀ✪

• $sinA = \frac{8}{17}$

• $cosA = \frac{15}{17}$

• $tanA = \frac{8}{15}$

★ᴇxᴘʟᴀɪɴᴀᴛɪᴏɴ★

☆ɢɪᴠᴇɴ☆

• A right triangle ABC right angled at B.
• AB = 15 cm, BC = 8 cm.

☆ᴛᴏ ғɪɴᴅ☆

• sinA, cosA, tanA

☆ᴄᴀʟᴄᴜʟᴀᴛɪᴏɴ☆

Since $∠ABC = 90º$, AC is the hypotenous.

Using Pythagoras Theorem,

$\to AC^2 = AB^2 + BC^2$

$\to AC^2 = 15^2 + 8^2$

$\to AC^2 = 225+ 64$

$\to AC^2 = 289$

$\to AC = 17$

1. sinA

$\to sinA = \frac{Opposite}{Hypotenous}$

$\to sinA = \frac{BC}{AC}$

$\to sinA = \frac{8}{17}$

2. cosA

$\to cosA = \frac{Adjacent}{Hypotenous}$

$\to cosA = \frac{AB}{AC}$

$\to cosA = \frac{15}{17}$

3. tanA

$\to tanA = \frac{Opposite}{Adjacent}$

$\to tanA = \frac{BC}{AB}$

$\to tanA = \frac{8}{15}$